Motor sequence learning: a study with positron emission tomography

Abstract

We have used positron emission tomography to study the functional anatomy of motor sequence learning. Subjects learned sequences of keypresses by trial and error using auditory feedback. They were scanned with eyes closed under three conditions: at rest, while performing a sequence that was practiced before scanning until overlearned, and while learning new sequences at the same rate of performance. Compared with rest, both sequence tasks activated the contralateral sensorimotor cortex to the same extent. Comparing new learning with performance of the prelearned sequence, differences in activation were identified in other areas. (1) Prefrontal cortex was only activated during new sequence learning. (2) Lateral premotor cortex was significantly more activated during new learning, whereas the supplementary motor area was more activated during performance of the prelearned sequence. (3) Activation of parietal association cortex was present during both motor tasks, but was significantly greater during new learning. (4) The putamen was equally activated by both conditions. (5) The cerebellum was activated by both conditions, but the activation was more extensive and greater in degree during new learning. There was an extensive decrease in the activity of prestriate cortex, inferotemporal cortex, and the hippocampus in both active conditions, when compared with rest. These decreases were significantly greater during new learning. We draw three main conclusions. (1) The cerebellum is involved in the process by which motor tasks become automatic, whereas the putamen is equally activated by sequence learning and retrieval, and may play a similar role in both. (2) When subjects learn new sequences of motor actions, prefrontal cortex is activated. This may reflect the need to generate new responses. (3) Reduced activity of areas concerned with visual processing, particularly during new learning, suggests that selective attention may involve depressing the activity of cells in modalities that are not engaged by the task.

Brain imaging of the central executive component of working memory

“…Moreover, since the frontal and parietal inferior areas were engaged by the two tasks at the same time, these results are in agreement with the hypothesis that overlapping cerebral activity is the physiological basis for interference in the dual-task condition. This hypothesis is furthermore supported by the observation that practice is associated with a decrease in interference between two tasks, as well as decreases in prefrontal and cingulate activity and thus presumably a decrease in overlapping activation [59,92].…”

Specific Language Impairment is not Specific to Language: the Procedural Deficit Hypothesis

“…The procedural system is composed of a network of several interconnected brain structures (De Renzi, 1989;Heilman et al, 1997;Hikosaka et al, 2000;Jenkins et al, 1994;Mishkin et al, 1984;Rizzolatti et al, 2000; Schacter and Tulving, 1994;Squire and Zola, 1996). Within the cerebrum, the system depends especially on structures in the left hemisphere (De Renzi, 1989;Heilman et al, 1997;Schluter et al, 2001).…”

“…(For the sake of simplicity, below we also refer to the system as the "procedural system".) The system underlies aspects of rule-learning (Knowlton et al, 1996;Poldrack et al, 1999), and is particularly important for acquiring and performing skills involving sequences -whether the sequences are serial or abstract, or sensori-motor or cognitive (Aldridge and Berridge, 1998;Boecker et al, 2002;Graybiel, 1995;Jenkins et al, 1994;Saint-Cyr et al, 1988;Willingham, 1998). Acquisition of the procedures is gradual, in that learning occurs on an ongoing basis during multiple trials.…”

“…Note that we use the term "procedural memory system" to refer only to one type of implicit, non-declarative, memory system (Squire and Knowlton, 2000), not all non-declarative or implicit memory systems. Moreover, we use the term to refer to the entire system involved in the learning, representation and use of procedural memories, not just to those parts of the system underlying the acquisition of new procedural knowledge (also see Ullman, in press-a).The procedural system is composed of a network of several interconnected brain structures (De Renzi, 1989;Heilman et al, 1997;Hikosaka et al, 2000;Jenkins et al, 1994;Mishkin et al, 1984;Rizzolatti et al, 2000; Schacter and Tulving, 1994;Squire and Zola, 1996). Within the cerebrum, the system depends especially on structures in the left hemisphere (De Renzi, 1989;Heilman et al, 1997;Schluter et al, 2001).…”

Intact procedural motor sequence learning in developmental coordination disorder

“…Learning is INTACT PROCEDURAL MOTOR SEQUENCE LEARNING 5 demonstrated by improvement in the speed of response across trials and, more specifically, by the difference in response latency between a random block of stimuli and the repeating sequence block, indicating clearly that skill learning was sequence-specific. Neuroimaging studies have demonstrated that procedural sequence learning is supported by the basal ganglia and the cerebellum (e.g., Jenkins, Brooks, Nixon, Frackowiak, & Passingham, 1994), and the SRT paradigm has been widely used to explore memory abilities in various neurological pathologies characterized by impairments in these regions, such as Parkinson's disease (e.g., Helmuth, Mayr, & Daum, 2000). In children, the SRT task has also been used to explore procedural learning in developmental disorders (e.g., Lum et al, 2012;Vicari et al, 2005) To our knowledge, only two studies have investigated the motor difficulties of children with DCD with the SRT paradigm.…”