We investigated the effects of 10 hours of practice on variations of the N-Back task to investigate the processes underlying possible expansion of the focus of attention within working memory. Using subtractive logic, we showed that random access (i.e., Sternberg-like search) yielded a modest effect (a 50% increase in speed) whereas the processes of forward access (i.e., retrieval in order, as in a standard N-Back task) and updating (i.e., changing the contents of working memory) were executed about 5 times faster after extended practice. We additionally found that extended practice increased working memory capacity as measured by the size of the focus of attention for the forward-access task, but not for variations where probing was in random order. This suggests that working memory capacity may depend on the type of search process engaged, and that certain working-memory-related cognitive processes are more amenable to practice than others.
The present study examined the impact of the phonological realization of morphosyntactic agreement within the inflectional phrase (IP) in written French, as revealed by ERPs. In two independent experiments, we varied the presence vs. absence of phonological cues to morphological variation. Of interest was whether a graded ERP response to these different conditions could be found in native speakers (Experiment 1), and whether non-native learners would benefit from the presence of phonological cues (Experiment 2). The results for native French speakers showed that compared to grammatically correct instances, phonologically realized inflectional errors produced a significant P600 response, which was statistically larger than that produced by errors that were silent. German L1 French L2 learners showed similar benefits of the phonological realization of morphemes. Phonologically realized errors produced a robust P600 response whereas silent errors produced no robust effects. Implications of these results are discussed in reference to previous studies of L2 acquisition of morphosyntax.
We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4s, light = 12s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value.
Time Perception; Rats; Multimodal
In addition to the classic finding that “sounds are judged longer than lights,” the timing of auditory stimuli is often more precise and accurate than is the timing of visual stimuli. In cognitive models of temporal processing, these modality differences are explained by positing that auditory stimuli more automatically capture and hold attention, more efficiently closing an attentional switch that allows the accumulation of pulses marking the passage of time (Block & Zakay, 1997; Meck, 1991; Penney, 2003). However, attention is a multifaceted construct, and there has been little attempt to determine which aspects of attention may be related to modality effects. We used visual and auditory versions of the Continuous Temporal Expectancy Task (CTET; O'Connell et al., 2009) a timing task previously linked to behavioral and electrophysiological measures of mind-wandering and attention lapses, and tested participants with or without the presence of a video distractor. Performance in the auditory condition was generally superior to that in the visual condition, replicating standard results in the timing literature. The auditory modality was also less affected by declines in sustained attention indexed by declines in performance over time. In contrast, distraction had an equivalent impact on performance in the two modalities. Analysis of individual differences in performance revealed further differences between the two modalities: Poor performance in the auditory condition was primarily related to boredom whereas poor performance in the visual condition was primarily related to distractibility. These results suggest that: 1) challenges to different aspects of attention reveal both modality-specific and nonspecific effects on temporal processing, and 2) different factors drive individual differences when testing across modalities.
interval timing; attention; modality; distraction; sustained attention; individual differences
As a fundamental part of our daily lives, visual word processing has received much attention in the psychological literature. Despite the well established advantage of perceiving letters in a word or in a pseudoword over letters alone or in random sequences using accuracy, a comparable effect using response times has been elusive. Some researchers continue to question whether the advantage due to word context is perceptual. We use the capacity coefficient, a well established, response time based measure of efficiency to provide evidence of word processing as a particularly efficient perceptual process to complement those results from the accuracy domain.
word perception; word superiority effect; capacity coefficient
This article reviews situations in which stimuli produce an increase or a decrease in nociceptive responses through basic associative processes and provides an associative account of such changes. Specifically, the literature suggests that cues associated with stress can produce conditioned analgesia or conditioned hyperalgesia, depending on the properties of the conditioned stimulus (e.g., contextual cues and audiovisual cues vs. gustatory and olfactory cues, respectively) and the proprieties of the unconditioned stimulus (e.g., appetitive, aversive, or analgesic, respectively). When such cues are associated with reducers of exogenous pain (e.g., opiates), they typically increase sensitivity to pain. Overall, the evidence concerning conditioned stress-induced analgesia, conditioned hyperalagesia, conditioned tolerance to morphine, and conditioned reduction of morphine analgesia suggests that selective associations between stimuli underlie changes in pain sensitivity.
pain; analgesia; hyperalgesia; morphine tolerance; conditioning
There has been little research on the fluency of language production and individual differences variables, such as intelligence and executive function. In this study, we report data from 106 participants who completed a battery of standardized cognitive tasks and a sentence production task. For the sentence production task, participants were presented with two objects and a verb and their task was to formulate a sentence. Four types of disfluency were examined: filled pauses (e.g. uh, um), unfilled pauses, repetitions, and repairs. Repetitions occur when the speaker suspends articulation and then repeats the previous word/phrase, and repairs occur when the speaker suspends articulation and then starts over with a different word/phrase. Hierarchical structural equation modeling revealed a significant relationship between repair disfluencies and inhibition. Conclusions focus on the role of individual differences in cognitive ability and their role in models and theories of language production.
language production; speech fluency; intelligence; executive function; disfluency; inhibitory control; inhibition
This present study examined accuracy and response latency of letter processing as a function of position within a horizontal array. In a series of 4 Experiments, target-strings were briefly (33 ms for Experiment 1 to 3, 83 ms for Experiment 4) displayed and both forward and backward masked. Participants then made a two alternative forced choice. The two alternative responses differed just in one element of the string, and position of mismatch was systematically manipulated. In Experiment 1, words of different lengths (from 3 to 6 letters) were presented in separate blocks. Across different lengths, there was a robust advantage in performance when the alternative response was different for the letter occurring at the first position, compared to when the difference occurred at any other position. Experiment 2 replicated this finding with the same materials used in Experiment 1, but with words of different lengths randomly intermixed within blocks. Experiment 3 provided evidence of the first position advantage with legal nonwords and strings of consonants, but did not provide any first position advantage for non-alphabetic symbols. The lack of a first position advantage for symbols was replicated in Experiment 4, where target-strings were displayed for a longer duration (83 ms). Taken together these results suggest that the first position advantage is a phenomenon that occurs specifically and selectively for letters, independent of lexical constraints. We argue that the results are consistent with models that assume a processing advantage for coding letters in the first position, and are inconsistent with the commonly held assumption in visual word recognition models that letters are equally processed in parallel independent of letter position.
letter-processing; serial position; visual word recognition
Previous masked priming research in word recognition has demonstrated that repetition priming is influenced by experiment-wise information structure, such as proportion of target repetition. Research using naturalistic tasks and eye-tracking has shown that people use linguistic knowledge to anticipate upcoming words. We examined whether the proportion of target repetition within an experiment can have a similar effect on anticipatory eye movements. We used a word-to-picture matching task (i.e., the visual world paradigm) with target repetition proportion carefully controlled. Participants’ eye movements were tracked starting when the pictures appeared, one second prior to the onset of the target word. Targets repeated from the previous trial were fixated more than other items during this preview period when target repetition proportion was high and less than other items when target repetition proportion was low. These results indicate that linguistic anticipation can be driven by short-term within-experiment trial structure, with implications for the generalization of priming effects, the bases of anticipatory eye movements, and experiment design.
anticipation; spoken-word comprehension; repetition priming; eye-tracking
The present study examined influences of semantic characteristics of objects in real-world scenes on allocation of attention as reflected in eye movement measures. Stimuli consisted of full-color photographic scenes, and within each scene, the semantic salience of two target objects was manipulated while the objects’ perceptual salience was kept constant. One of the target objects was either inconsistent or consistent with the scene category. In addition, the second target object was either smoking-related or neutral. Two groups of college students, namely current cigarette smokers (N = 18) and non-smokers (N = 19), viewed each scene for ten seconds while their eye movements were recorded. While both groups showed preferential allocation of attention to inconsistent objects, smokers also selectively attended to smoking-related objects. Theoretical implications of the results are discussed.
visual attention; scene perception; cognitive bias; tobacco smoking
Visual search plays an important role in guiding behavior. Children have more difficulty performing conjunction search tasks than adults. The present research evaluates whether developmental differences in children's ability to organize serial visual search (i.e., search organization skills) contribute to performance limitations in a typical conjunction search task. We evaluated 134 children between the ages of 2 and 17 on separate tasks measuring search for targets defined by a conjunction of features or by distinct features. Our results demonstrated that children organize their visual search better as they get older. As children's skills at organizing visual search improve they become more accurate at locating targets with conjunction of features amongst distractors, but not for targets with distinct features. Developmental limitations in children's abilities to organize their visual search of the environment are an important component of poor conjunction search in young children. In addition, our findings provide preliminary evidence that, like other visuospatial tasks, exposure to reading may influence children's spatial orientation to the visual environment when performing a visual search.
visual search; search organization; executive function; normal development; search orientation; conjunction search
The minimum variance theory proposes that motor commands are corrupted by signal-dependent noise and smooth trajectories with low noise levels are selected to minimize endpoint error and endpoint variability. The purpose of the study was to determine the contribution of trajectory smoothness to the endpoint accuracy and endpoint variability of rapid multi-joint arm movements. Young and older adults performed arm movements (4 blocks of 25 trials) as fast and as accurately as possible to a target with the right (dominant) arm. Endpoint accuracy and endpoint variability along with trajectory smoothness and error were quantified for each block of trials. Endpoint error and endpoint variance were greater in older adults compared with young adults, but decreased at a similar rate with practice for the two age groups. The greater endpoint error and endpoint variance exhibited by older adults were primarily due to impairments in movement extent control and not movement direction control. The normalized jerk was similar for the two age groups, but was not strongly associated with endpoint error or endpoint variance for either group. However, endpoint variance was strongly associated with endpoint error for both the young and older adults. Finally, trajectory error was similar for both groups and was weakly associated with endpoint error for the older adults. The findings are not consistent with the predictions of the minimum variance theory, but support and extend previous observations that movement trajectories and endpoints are planned independently.
aging; neural noise; skill; practice
Studies have shown that false memories can be implanted via innocuous suggestions, and that these memories can play a role in shaping people’s subsequent attitudes and preferences. The current study explored whether participants (N=147) who received a false suggestion that they had become ill drinking a particular type of alcohol would increase their confidence that the event had occurred, and whether their new-found belief would subsequently affect their alcohol preferences. Results indicated that participants who received a suggestion that they had gotten sick drinking rum or vodka before the age of 16 reported increased confidence that the suggested experience had occurred. Moreover, participants who received a false alcohol suggestion also showed a strong trend to report diminished preference for the specified type of alcohol after the false suggestion. Implantation of a false memory related to one’s past drinking experiences may influence current drink preferences and could be an important avenue for further exploration in the development of alcohol interventions.
Temporal order memory, or remembering the order of events, is critical for everyday functioning and is difficult for patients with mild cognitive impairment (MCI). It is currently unclear whether these patients have difficulty acquiring and/or retaining such information and whether deficits in these patients are in excess of “normal” age-related declines. Therefore, the current study examined age and disease-related changes in temporal order memory as well as whether memory load played a role in such changes. Young controls (n=25), older controls (n=34), and MCI patients (n=32) completed an experimental task that required the reconstruction of sequences that were 3, 4, or 5-items in length both immediately after presentation (i.e., immediate recall) and again following a 10-minute delay (i.e., delayed recall). During the immediate recall phase, there was an effect of age largely due to reduced performance at the two longest span lengths. Older controls and MCI patients only differed during the 5 span (controls > MCI). During the delayed recall, however, there were significant effects of both age and MCI regardless of span length. In MCI patients, immediate recall was significantly correlated with measures of executive functioning while delayed recall performance was only related to other memory tests. These findings suggest that MCI patients experience initial temporal order memory deficits at the point when information begins to exceed working memory capacity and become dependent on medial temporal lobe functioning. Longer-term deficits are due to an inability to retain information, consistent with the characteristic medial temporal lobe dysfunction in MCI.
Two experiments examined the relations among adult aging, mind wandering, and executive-task performance, following from surprising laboratory findings that older adults report fewer task-unrelated thoughts (TUTs) than do younger adults (e.g., Giambra, 1989; Jackson & Balota, 2011). Because older adults may experience more ability- and performance-related worry during cognitive tasks in the laboratory, and because these evaluative thoughts (known as task-related interference, “TRI”) might be sometimes misclassified by subjects as task-related, we asked subjects to distinguish task-related thoughts from TRI and TUTs when probed during ongoing tasks. In Experiment 1, younger and older adults completed either a go/no-go or a vigilance version of a sustained attention to response task (SART). Older adults reported more TRI and fewer TUTs than did younger adults while also performing more accurately. In Experiment 2, subjects completed either a 1- or 2-back version of the n-back task. Older adults again reported more TRI and fewer TUTs than younger adults in both versions, while performing better than younger adults in the 1-back and worse in the 2-back. Across experiments, older adults’ reduced TUT rates were independent of performance relative to younger adults. And, although older adults consistently reported more TRI and less mind wandering than did younger adults, overall they reported more on-task thoughts. TRI cannot, therefore, account completely for prior reports of decreasing TUTs with aging. We discuss the implications of these results for various theoretical approaches to mind-wandering.
aging; mind wandering; executive control; consciousness; working memory
The idea that video games or computer-based applications can improve cognitive function has led to a proliferation of programs claiming to “train the brain.” However, there is often little scientific basis in the development of commercial training programs, and many research-based programs yield inconsistent or weak results. In this study, we sought to better understand the nature of cognitive abilities tapped by casual video games and thus reflect on their potential as a training tool. A moderately large sample of participants (n=209) played 20 web-based casual games and performed a battery of cognitive tasks. We used cognitive task analysis and multivariate statistical techniques to characterize the relationships between performance metrics. We validated the cognitive abilities measured in the task battery, examined a task analysis-based categorization of the casual games, and then characterized the relationship between game and task performance. We found that games categorized to tap working memory and reasoning were robustly related to performance on working memory and fluid intelligence tasks, with fluid intelligence best predicting scores on working memory and reasoning games. We discuss these results in the context of overlap in cognitive processes engaged by the cognitive tasks and casual games, and within the context of assessing near and far transfer. While this is not a training study, these findings provide a methodology to assess the validity of using certain games as training and assessment devices for specific cognitive abilities, and shed light on the mixed transfer results in the computer-based training literature. Moreover, the results can inform design of a more theoretically-driven and methodologically-sound cognitive training program.
Working memory; Reasoning; Fluid intelligence; Video games; Cognitive training; Casual games
Research has identified multiple category-learning systems with each being “tuned” for learning categories with different task demands and each governed by different neurobiological systems. Rule-based (RB) classification involves testing verbalizable rules for category membership while the information-integration (II) classification requires the implicit learning of stimulus-response mappings. In the first study to directly test rule priming with RB and II category learning, we investigated the influence of the availability of information presented at the beginning of the task. Participants viewed lines that varied in length, orientation, and position on the screen, and were primed to focus on stimulus dimensions that were relevant or irrelevant to the correct classification rule. In Experiment 1, we used an RB category structure, and in Experiment 2, we used an II category structure. Accuracy and model-based analyses suggested that a focus on relevant dimensions improves RB task performance later in learning while a focus on an irrelevant dimension improves II task performance early in learning.
categorization; memory systems; dimension relevance; priming; category learning
Many educated adults possess exact mathematical abilities in addition to an approximate, intuitive sense of number, often referred to as the Approximate Number System (ANS). Here we investigate the link between ANS precision and mathematics performance in adults by testing participants on an ANS-precision test and collecting their scores on the Scholastic Aptitude Test (SAT), a standardized college-entrance exam in the USA. In two correlational studies, we found that ANS precision correlated with SAT-Quantitative (i.e., mathematics) scores. This relationship remained robust even when controlling for SAT-Verbal scores, suggesting a small but specific relationship between our primitive sense for number and formal mathematical abilities.
Approximate Number System; math ability; Weber fraction; number comparison
We investigated whether the mere presentation of single-digit Arabic numbers activates their magnitude representations using a visually-presented symbolic same–different task for 20 adults and 15 children. Participants saw two single-digit Arabic numbers on a screen and judged whether the numbers were the same or different. We examined whether reaction time in this task was primarily driven by (objective or subjective) perceptual similarity, or by the numerical difference between the two digits. We reasoned that, if Arabic numbers automatically activate magnitude representations, a numerical function would best predict reaction time; but if Arabic numbers do not automatically activate magnitude representations, a perceptual function would best predict reaction time. Linear regressions revealed that a perceptual function, specifically, subjective visual similarity, was the best and only significant predictor of reaction time in adults and in children. These data strongly suggest that, in this task, single-digit Arabic numbers do not necessarily automatically activate magnitude representations in adults or in children. As the first study to date to explicitly study the developmental importance of perceptual factors in the symbolic same–different task, we found no significant differences between adults and children in their reliance on perceptual information in this task. Based on our findings, we propose that visual properties may play a key role in symbolic number judgements.
•Single-digit Arabic numbers do not automatically activate magnitude representations.•This is true for both adults and children.•Subjective visual properties may play a key role in symbolic number judgments.
Symbolic numbers; Numerical cognition; Automaticity; Magnitude representations; Same–different task
Mental rotation and number representation have both been studied widely, but although mental rotation has been linked to higher-level mathematical skills, to date it has not been shown whether mental rotation ability is linked to the most basic mental representation and processing of numbers. To investigate the possible connection between mental rotation abilities and numerical representation, 43 participants completed four tasks: 1) a standard pen-and-paper mental rotation task; 2) a multi-digit number magnitude comparison task assessing the compatibility effect, which indicates separate processing of decade and unit digits; 3) a number-line mapping task, which measures precision of number magnitude representation; and 4) a random number generation task, which yields measures both of executive control and of spatial number representations. Results show that mental rotation ability correlated significantly with both size of the compatibility effect and with number mapping accuracy, but not with any measures from the random number generation task. Together, these results suggest that higher mental rotation abilities are linked to more developed number representation, and also provide further evidence for the connection between spatial and numerical abilities.
•We show a link between mental rotation ability (MRA) and numerical representation.•MRA correlated with a measure of holding concurrent multiple number representations.•MRA correlated with a measure of number representation precision (number line task).•MRA did not correlate with an executive control task (random number generation).•These findings strengthen the link observed between spatial and numerical abilities.
Mental rotation; Numerical representation; Compatibility effect; Numerical cognition; Number line; Spatial abilities
Angular path integration refers to the ability to maintain an estimate of self-location after a rotational displacement by integrating internally-generated (idiothetic) self-motion signals over time. Previous work has found that non-sensory inputs, namely spatial memory, can play a powerful role in angular path integration (Arthur et al., 2007, 2009). Here we investigated the conditions under which spatial memory facilitates angular path integration. We hypothesized that the benefit of spatial memory is particularly likely in spatial updating tasks in which one’s self-location estimate is referenced to external space. To test this idea, we administered passive, nonvisual body rotations (ranging 40° – 140°) about the yaw axis and asked participants to use verbal reports or open-loop manual pointing to indicate the magnitude of the rotation. Prior to some trials, previews of the surrounding environment were given. We found that when participants adopted an egocentric frame of reference, the previously-observed benefit of previews on within-subject response precision was not manifested, regardless of whether remembered spatial frameworks were derived from vision or spatial language. We conclude that the powerful effect of spatial memory is dependent on one’s frame of reference during self-motion updating.
spatial memory; path integration; vestibular navigation; manual pointing; perception and action
Multi-tasking can increase susceptibility to distraction, affecting whether irrelevant objects capture attention. Similarly, people with depression often struggle to concentrate when performing cognitively demanding tasks. This parallel suggests that depression is like multi-tasking. To test this idea, we examined relations between self-reported levels of anhedonic depression (a dimension that reflects the unique aspects of depression not shared with anxiety or other forms of distress) and attention capture by salient items in a visual search task. Furthermore, we compared these relations to the effects of performing a concurrent auditory task on attention capture. Strikingly, both multi-tasking and elevated levels of anhedonic depression were associated with increased capture by uniquely colored items, but decreased capture by abruptly appearing items. At least with respect to attention capture and distraction, depression seems to be functionally comparable to juggling a second, unrelated cognitive task.
depression; anhedonic depression; attention capture; multi-tasking; distractibility
In three N-Back experiments, we investigated components of the process of working memory (WM) updating, more specifically access to items stored outside the focus of attention and transfer from the focus to the region of WM outside the focus. We used stimulus complexity as a marker. We found that when WM transfer occurred under full attention, it was slow and highly sensitive to stimulus complexity, much more so than WM access. When transfer occurred in conjunction with access, however, it was fast and no longer sensitive to stimulus complexity. Thus the updating context altered the nature of WM processing: The dual-task situation (transfer in conjunction with access) drove memory transfer into a more efficient mode, indifferent to stimulus complexity. In contrast, access times consistently increased with complexity, unaffected by the processing context. This study reinforces recent reports that retrieval is a (perhaps the) key component of working memory functioning.
The legibility of the letters in the Latin alphabet has been measured numerous times since the beginning of experimental psychology. To identify the theoretical mechanisms attributed to letter identification, we report a comprehensive review of literature, spanning more than a century. This review revealed that identification accuracy has frequently been attributed to a subset of three common sources: perceivability, bias, and similarity. However, simultaneous estimates of these values have rarely (if ever) been performed. We present the results of two new experiments which allow for the simultaneous estimation of these factors, and examine how the shape of a visual mask impacts each of them, as inferred through a new statistical model. Results showed that the shape and identity of the mask impacted the inferred perceivability, bias, and similarity space of a letter set, but that there were aspects of similarity that were robust to the choice of mask. The results illustrate how the psychological concepts of perceivability, bias, and similarity can be estimated simultaneously, and how each make powerful contributions to visual letter identification.
Letter similarity; Choice theory
Separate cognitive processes govern the inhibitory control of manual and oculomotor movements. Despite this fundamental distinction, little is known about how these inhibitory control processes relate to more complex domains of behavioral functioning. This study sought to determine how these inhibitory control mechanisms relate to broadly defined domains of impulsive behavior. Thirty adults with attention-deficit/hyperactivity disorder (ADHD) and 28 comparison adults performed behavioral measures of inhibitory control and completed impulsivity inventories. Results suggest that oculomotor inhibitory control, but not manual inhibitory control, is related to specific domains of self-reported impulsivity. This finding was limited to the ADHD group; no significant relations between inhibitory control and impulsivity were found in comparison adults. These results highlight the heterogeneity of inhibitory control processes and their differential relations to different facets of impulsivity.
impulsivity; inhibitory control; manual; oculomotor; ADHD