Neurocognitive Contributions to Motor Skill Learning: The Role of Working Memory

ABSTRACT

Researchers have begun to delineate the precise nature and neural correlates of the cognitive processes that contribute to motor skill learning. The authors review recent work from their laboratory designed to further understand the neurocognitive mechanisms of skill acquisition. The authors have demonstrated an important role for spatial working memory in 2 different types of motor skill learning, sensorimotor adaptation and motor sequence learning. They have shown that individual differences in spatial working memory capacity predict the rate of motor learning for sensorimotor adaptation and motor sequence learning, and have also reported neural overlap between a spatial working memory task and the early, but not late, stages of adaptation, particularly in the right dorsolateral prefrontal cortex and bilateral inferior parietal lobules. The authors propose that spatial working memory is relied on for processing motor error information to update motor control for subsequent actions. Further, they suggest that working memory is relied on during learning new action sequences for chunking individual action elements together.     

Does working memory capacity predict cross-modally induced failures of awareness?

People often fail to notice unexpected stimuli when they are focusing attention on another task. Most studies of this phenomenon address visual failures induced by visual attention tasks (inattentional blindness). Yet, such failures also occur within audition (inattentional deafness), and people can even miss unexpected events in one sensory modality when focusing attention on tasks in another modality. Such cross-modal failures are revealing because they suggest the existence of a common, central resource limitation. And, such central limits might be predicted from individual differences in cognitive capacity. We replicated earlier evidence, establishing substantial rates of inattentional deafness during a visual task and inattentional blindness during an auditory task. However, neither individual working memory capacity nor the ability to perform the primary task predicted noticing in either modality. Thus, individual differences in cognitive capacity did not predict failures of awareness even though the failures presumably resulted from central resource limitations.     

The roles of sequencing and verbal working memory in sentence comprehension deficits in Parkinson's disease

Studies of sentence comprehension deficits in Parkinson's disease (PD) patients suggest that language processing involves circuits connecting subcortical and cortical regions. Anatomically segregated neural circuits appear to support different cognitive and motor functions. To investigate which functions are implicated in PD comprehension deficits, we tested comprehension, verbal working memory span, and cognitive set-switching in a non-linguistic task in 41 PD patients; we also obtained speech measurements reflecting motor sequencing processes that may be involved in articulatory rehearsal within working memory. Comprehension of sentences with center-embedded or final relative clauses was impaired when they could not be understood from lexical semantic content alone. Overall comprehension error rates correlated strongly with impaired set-switching and significantly with reduced working memory span and speech motor sequencing deficits. Correlations with comprehension of different sentence structures indicate that these impairments do not represent a single deficit; rather, PD comprehension deficits appear to arise from several independent mechanisms. Deficits in cognitive set-switching or underlying inhibitory processes may compromise the ability to process relative clauses. Deficits in verbal working memory appear to impair comprehension of long-distance dependencies. Speech sequencing correlated with neither set-switching nor verbal working memory span, consistent with their being supported by independent, segregated cortico-subcortical circuits.     

The relationship between working memory capacity and cortical activity during performance of a novel motor task

ObjectivesThis study assessed whether individual differences in working memory capacity influenced verbal-analytical processes when performing a novel motor skill.DesignParticipants performed a tennis-hitting task in two conditions: no pressure and high-pressure.MethodsEighteen young adults participated in the study. EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies was recorded during performance in each condition. Verbal and visuo-spatial working memory capacity were assessed using the Automated Working Memory Assessment.ResultsNo differences were found between the two conditions for hitting performance and EEG activity. However, across both conditions, verbal and visuo-spatial working memory were significant predictors of EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies. Larger verbal working memory capacity was associated with greater coherence while the opposite trend was observed for visuo-spatial working memory capacity.ConclusionsThese results indicate that larger verbal working memory capacity is associated with a greater tendency to use explicit processes during motor performance, whereas larger visuo-spatial working memory capacity is associated more with implicit processes. The findings are discussed with relevance to the theory of implicit motor learning.     

The link between brain learning, attention, and consciousness

The processes whereby our brains continue to learn about a changing world in a stable fashion throughout life are proposed to lead to conscious experiences. These processes include the learning of top-down expectations, the matching of these expectations against bottom-up data, the focusing of attention upon the expected clusters of information, and the development of resonant states between bottom-up and top-down processes as they reach an attentive consensus between what is expected and what is there in the outside world. It is suggested that all conscious states in the brain are resonant states and that these resonant states trigger learning of sensory and cognitive representations. The models which summarize these concepts are therefore called Adaptive Resonance Theory, or ART, models. Psychophysical and neurobiological data in support of ART are presented from early vision, visual object recognition, auditory streaming, variable-rate speech perception, somatosensory perception, and cognitive-emotional interactions, among others. It is noted that ART mechanisms seem to be operative at all levels of the visual system, and it is proposed how these mechanisms are realized by known laminar circuits of visual cortex. It is predicted that the same circuit realization of ART mechanisms will be found in the laminar circuits of all sensory and cognitive neocortex. Concepts and data are summarized concerning how some visual percepts may be visibly, or modally, perceived, whereas amodal percepts may be consciously recognized even though they are perceptually invisible. It is also suggested that sensory and cognitive processing in the What processing stream of the brain obey top-down matching and learning laws that are often complementary to those used for spatial and motor processing in the brain's Where processing stream. This enables our sensory and cognitive representations to maintain their stability as we learn more about the world, while allowing spatial and motor representations to forget learned maps and gains that are no longer appropriate as our bodies develop and grow from infanthood to adulthood. Procedural memories are proposed to be unconscious because the inhibitory matching process that supports these spatial and motor processes cannot lead to resonance.     

Development of Indirect Measures of Conscientiousness: Combining a Facets Approach and Network Analysis

Because indirect measures of personality self‐concepts such as the Implicit Association Test (IAT) allow tapping into automatic processes, they can offer advantages over self‐report measures. However, prior investigations have led to mixed results regarding the validity of indirect measures of conscientiousness. We suggest that these results might be due to a failure to consider the different facets of conscientiousness. These facets are of crucial importance because they are associated differentially with other psychobiological constructs and they are also characterized by different mechanisms. Therefore, focusing on facets while developing indirect measures of conscientiousness may improve the validity of such measures. In Study 1, we conducted a psycholexical investigation to develop one IAT for each conscientiousness facet. In Study 2, we examined the convergent and discriminant validities of each facet IAT in relation to self‐report measures, peer‐report measures and self‐report behavioural indicators, and we investigated differential associations of the conscientiousness facets with working memory capacity and self‐control. We employed network analysis as a novel approach to elucidate differential relationships involving personality facets. The results corroborated the convergent and discriminant validity of the conscientiousness facet IATs with self‐reports and showed that the conscientiousness facets were differentially associated with working memory capacity and with self‐control. Copyright © 2015 European Association of Personality Psychology     

The relation between measures of cognitive and motor functioning in 5- to 6-year-old children

Specific relations between executive functions (working memory capacity, planning and problem-solving, inhibitory control) and motor skill performance (anticipatory motor planning, manual dexterity) were examined in 5- to 6-year-old children (N = 40). Results showed that the two motor skill components were not correlated. Additionally, it was found that response planning performance was a significant predictor of anticipatory motor planning performance, whereas inhibitory control and working memory capacity measures were significant predictors of manual dexterity scores. Taken together, these results suggest that cognitive and motor skills are linked, but that manual dexterity and anticipatory motor planning involve different specialized skills. The current study provides support for specific relations between cognitive and motor performance, which has implications for early childhood cognitive-motor training and intervention programs.     

Scheduling Processes in Working Memory: Instructions Control the Order of Memory Search and Mental Arithmetic

Humans must often use working memory to execute processes one at a time because of its limited capacity. Two experiments tested where limits in access to working memory occur. Subjects searched a short-term memory set for one stimulus digit and performed mental arithmetic with another stimulus digit. In one experiment, they were told to carry out the mental arithmetic before the memory search and to make the arithmetic response first. In the other, they were instructed to perform the tasks in the opposite order. The overt responses were executed in the prescribed order. Moreover, the covert working memory processes were executed in the prescribed order, as revealed by a critical path network analysis of reaction times. Results are explained in terms of a double-bottleneck model in which central processes and responses are constrained to be carried out for one task at a time.     

Deconstructing the effect of self-directed study on episodic memory

Self-directed learning is often associated with better long-term memory retention; however, the mechanisms that underlie this advantage remain poorly understood. This series of experiments was designed to “deconstruct” the notion of self-directed learning, in order to better identify the factors most responsible for these improvements to memory. In particular, we isolated the memory advantage that comes from controlling the content of study episodes from the advantage that comes from controlling the timing of those episodes. Across four experiments, self-directed learning significantly enhanced recognition memory, relative to passive observation. However, the advantage for self-directed learning was found to be present even under extremely minimal conditions of volitional control (simply pressing a button when a participant was ready to advance to the next item). Our results suggest that improvements to memory following self-directed encoding may be related to the ability to coordinate stimulus presentation with the learner’s current preparatory or attentional state, and they highlight the need to consider the range of cognitive control processes involved in and influenced by self-directed study.     

The relationship between executive functions,episodic feeling-of-knowing and confidence judgements

Metamemory processes and executive control may be related, given that both are frontally mediated. However, previous behavioural research has been limited in identifying common processes driving this somewhat weak relationship partly because they mostly relied upon global executive measures and composite scores of executive function (EF). The present study investigated the relationship between specific EFs (task shifting, interference resolution), working memory capacity and feeling-of-knowing (FOK) and confidence judgements (CONF) in an episodic memory task. We found that, of the EFs, only task-switching performance was correlated with FOK accuracy and proposed a shared mechanism that may be at play in both task-switching and FOK judgements. We also demonstrated that interference resolution and episodic memory measures were related, suggesting strategic influences on memory retrieval. Finally, we found a strong consistency in the strength and accuracy of FOK and CONF judgements, possibly due to retrieval-based mechanisms in both types of judgements.     

Motor affordance and its role for visual working memory: evidence from fMRI studies

We examined the role of motor affordances of objects for working memory retention processes. Three experiments are reported in which participants passively viewed pictures of real world objects or had to retain the objects in working memory for a comparison with an S2 stimulus. Brain activation was recorded by means of functional magnetic resonance imaging (fMRI). Retaining information about objects for which hand actions could easily be retrieved (manipulable objects) in working memory activated the hand region of the ventral premotor cortex (PMC) contralateral to the dominant hand. Conversely, nonmanipulable objects activated the left inferior frontal gyrus. This suggests that working memory for objects with motor affordance is based on motor programs associated with their use. An additional study revealed that motor program activation can be modulated by task demands: Holding manipulable objects in working memory for an upcoming motor comparison task was associated with left ventral PMC activation. However, retaining the same objects for a subsequent size comparison task led to activation in posterior brain regions. This suggests that the activation of hand motor programs are under top down control. By this they can flexibly be adapted to various task demands. It is argued that hand motor programs may serve a similar working memory function as speech motor programs for verbalizable working memory contents, and that the premotor system mediates the temporal integration of motor representations with other task-relevant representations in support of goal oriented behavior.     

Electromyographic evidence for response conflict in the exclude recognition task

How do memory retrieval processes lead to overt responses in strategic recognition tasks (responding “old” to one class of familiar stimulus and “new” to another)? Many current theories of memory retrieval ignore the response requirements in such memory tasks, instead modeling them using memory processes (e.g., familiarity and recollection) alone (see Yonelinas, 2002). We argue that strategic recognition involves conflict in response processing similar to canonical conflict tasks (e.g., the Stroop task). The parallel task set (PTS) model (Seymour, 2001) accounts for performance in strategic recognition tasks (e.g., the exclude recognition task) by suggesting that motor response conflict occurs when one responds “new” to familiar stimuli. We tested this prediction using surface electromyography, a measure incontrovertibly related to motor execution. Overall, results are consistent with the PTS model’s assumption that recognition, motor, and control processes interact in strategic retrieval tasks. The implications of these data for models of memory retrieval and response conflict are discussed.     

Voluntary timing and brain function: an information processing approach.

This article takes an information processing perspective to review current understanding of brain mechanisms of human voluntary timing. Theoretical accounts of timing of the production of isochronous tapping and rhythms and of bimanual responding repetitive responding are reviewed. The mapping of higher level temporal parameter setting and memory processes and of lower level motor implementation process onto cortical and subcortical brain structures is discussed in relation to evidence from selective lesions in a range of neurological motor disorders. Brain activation studies that have helped identify key brain structures involved in the control of timing are reviewed.     

Applying a dual process model of self-regulation: The association between executive working memory capacity,negative urgency,and negative mood induction on pre-potent response inhibition

This study tested a dual-process model of self-control where the combination of high impulsivity (negative urgency – NU), weak reflective/control processes (low executive working memory capacity – E-WMC), and a cognitive load is associated with increased failures to inhibit pre-potent responses on a cued go/no-go task. Using a within-subjects design, a cognitive load with and without negative emotional load was implemented to consider situational factors. Results suggested that: (1) high NU was associated with low E-WMC; (2) low E-WMC significantly predicted more inhibitory control failures across tasks; and (3) there was a significant interaction of E-WMC and NU, revealing those with low E-WMC and high NU had the highest rates of inhibitory control failures on all conditions of the task. In conclusion, results suggest that while E-WMC is a strong independent predictor of inhibitory control, NU provides additional information for vulnerability to problems associated with self-regulation.     

Orienting attention to locations in mental representations

Many cognitive processes depend on our ability to hold information in mind, often well beyond the offset of the original sensory input. The capacity of this visual short-term memory (VSTM) is limited to around three to four items. Recent research has demonstrated that the content of VSTM can be modulated by top-down attentional biases. This has been demonstrated using retrodictive spatial cues, termed "retro-cues," which orient subjects' attention to spatial locations within VSTM. In the present article, we tested whether the use of these cues is modulated by memory load and cue delay. There are a number of important conclusions: (1) Top-down biases can operate on very brief iconic traces as well as on older VSTM representations (Exp. 1). (2) When operating within capacity, subjects use the cue to prioritise where they initiate their memory search, rather than to discard uncued items (Exps. 2 and 3). (3) When capacity is exceeded, there is little benefit to top-down biasing relative to a neutral condition; however, unattended items are lost, with there being a substantial cost of invalid spatial cueing (Exp. 3). (4) These costs and benefits of orienting spatial attention differ across iconic memory and VSTM representations when VSTM capacity is exceeded (Exp. 4).     

An examination of the seductive details effect in terms of working memory capacity

Previous work on learning from text has demonstrated that although illustrated text can enhance comprehension, illustrations can also sometimes lead to poor learning outcomes when they are not relevant to understanding the text This phenomenon is known as the seductive details effect. The first experiment was designed to test whether the ability to control one's attention, as measured by working memory span tasks, would influence the processing of a scientific text that contained seductive (irrelevant) images, conceptually relevant images, or no illustrations. Understanding was evaluated using both an essay response and an inference verification task. Results indicated that low working memory capacity readers are especially vulnerable to the seductive details effect. In the second experiment, this issue was explored further, using eye-tracking methodology to evaluate the reading patterns of individuals who differed in working memory capacity as they read the same seductively illustrated scientific text Results indicated that low working memory individuals attend to seductive illustrations more often than not and, also, for a longer duration than do those individuals high in working memory capacity.     

Individual differences in everyday retrospective memory failures

The present study examined individual differences in everyday retrospective memory failures. Undergraduate students completed various cognitive ability measures in the laboratory and recorded everyday retrospective memory failures in a diary over the course of a week. The majority of memory failures were forgetting information pertaining to exams and homework, forgetting names, and forgetting login and ID information. Using latent variable techniques the results also suggested that individual differences in working memory capacity and retrospective memory were related to some but not all everyday memory failures. Furthermore, everyday memory failures predicted SAT scores and partially accounted for the relation between cognitive abilities and SAT scores. These results provide important evidence for individual differences in everyday retrospective memory failures as well as important evidence for the ecological validity of laboratory measures of working memory capacity and retrospective memory.     

The effects of mindfulness on executive processes and autobiographical memory specificity

Previous studies have found that mindfulness training reduces overgeneral memories and increases autobiographical memory specificity (e.g., [Williams, J. M. G., Teasdale, J. D., Segal, Z. V., & Soulsby, J. (2000). Mindfulness-based cognitive therapy reduces overgeneral autobiographical memory in formerly depressed patients. Journal of Abnormal Psychology, 109, 150-155]). However, little work has investigated the mechanisms underlying this effect. The present study explored the role of executive processes as a mediator of MBCT effects in an unselected sample. An autobiographical memory task, a cognitive inhibition task, a motor inhibition task, a cognitive flexibility task and a motor flexibility task were administered before and after intervention. Compared to matched controls, MBCT participants showed increased autobiographical memory specificity, decreased overgenerality, and improved cognitive flexibility capacity and capacity to inhibit cognitive prepotent responses. Mediational analyses indicated that changes in cognitive flexibility partially mediate the impact of MBCT on overgeneral memories. Results are discussed in terms of Conway's [2005. Memory and the self. Journal of Memory and Language, 53, 594-628] autobiographical memory model.     

Motor expertise modulates movement processing in working memory

A substantial amount of literature has demonstrated individuals' tendency to code verbally a series of movements for subsequent recall. However, the mechanisms underlying movement encoding remain unclear. In this paper, I argue that sensorimotor expertise influences the involvement of motor processes to store movements in working memory. Experts in motor activities and individuals with limited motor expertise were compared in three experimental conditions assessing movement recall: (a) without suppression task, (b) with verbal suppression, and (c) with motor suppression. Athletes outperformed controls in movement recall, but the suppression tasks affected the two groups differently. Verbal suppression affected controls more than athletes, whereas the effect was reversed with motor suppression. Together, these findings suggest that controls and athletes favor different mechanisms to encode movements, either based on verbal or on motor processes, providing further evidence for a tight relationship between sensorimotor and cognitive processes.     

False memories and aging

Although memory processes and systems usually operate reliably, they are sometimes prone to distortions and illusions. Here we review evidence indicating that cognitive aging is often associated with increased susceptibility to various kinds of false recollections. Accumulating data indicate that older adults frequently have special difficulties recollecting the source of information, which in turn renders them vulnerable to confusing perceived and imagined experiences, and to related kinds of memory distortions. Evidence from studies of false recall and recognition indicate that older adults are sometimes more likely than younger adults to remember events that never happened, reflecting the influence of indistinct encoding of events and the use of lenient criteria during retrieval. Neuroimaging studies suggest that age-related changes in medial temporal and frontal regions may play a role in the altered functioning of specific encoding and retrieval processes that give rise to memory distortions. Future studies of aging and false memories are likely to provide a promising avenue for illuminating basic mechanisms of memory distortion.