The Basal Ganglia and Chunking of Action Repertoires

“The consolidation of efficient action repertoires aimed at obtaining rewards depends on the dorsal striatum (Graybiel 1998, Packard & Knowlton 2002, Barnes et al. 2005, Vanderschuren et al. www.annualreviews.org • Neural Mechanisms of Addiction 571 A nn u.”

“…part of the process by which action sequences are chunked for representation as a result of habit learning: When they are packaged as a unit ready for expression, the boundaries of the unit are marked and the behavioral steps unfold from the first to the last boundary marker (Graybiel 1998).”

“The hypothesis that the basal ganglia mediate S-R habit learning has gained support from studies in rats (e.g., Graybiel 1998; Jog et al. 1999; Kesner et al. 1993; McDonald & White 1993, 1994; Packard et al. 1989; Packard & McGaugh 1992, 1996; Packard & Teather 1997, 1998; White 1997), monkeys…”

“† LTP of the corticostriatal synapse, believed to be important for habit formation [ 74 ], requires activation of mGluR1 and mGluR5 [75].”

“…learning (RL) research with animals identified a behavioral criterion for detecting habit performance, involving insensitivity to changes in rewarding outcomes (Dickinson 1985), and neuroscience began to identify the brain regions and circuits involved in habitual behavior (Graybiel 1998).”

“Specifically, the associative learning underlying habits is characterized by the slow, incremental accrual of information over time in procedural memory (see Graybiel, 1998; Packard & Knowlton, 2002; although also see Pasupathy & Miller, 2005).”

“The involvement of neostriatum in habit formation could be related to the hypothesized role of the basal ganglia in promoting the development of action sequences or ''chunking'' of components of instrumental behavior (Graybiel, 1998; Matsumoto et al., 1999).”

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“Many studies have suggested that the associative and the sensorimotor regions of the dorsal striatum may likewise play distinct roles in instrumental learning, with the former involved in the formation of action–outcome associations and the latter in stimulus–response (S–R) associations (Graybiel, 1998; Hikosaka et al…”

“One possibility is that the prefrontalbasal ganglia circuitry – known to play a role in building sequences of actions (Graybiel, 1995; Graybiel, 1998) – evolved”

“One might argue, then, that simple actions should take the place of strategies as one of the three basic categories of characteristic adaptation, but a good reason exists to decline this option: Collections of actions and subgoals that form coherent strategies for particular larger goals are chunked into representatio…”

“Activity patterns of striatal neurons were modified during the course of stimulus–response learning, and it has been suggested that the neostriatum acts to “chunk” the representations of motor and cognitive processes so that they can be executed as units (Graybiel 1998).”

“In this regard there are numerous papers that suggest that the striatum is involved in mediating cognitive performance (Graybiel, 1998; Shear et al., 1998; Tanila et al., 1998).”

“As shown in Figure 6, in one of the highest information compression ratios in the central nervous system (CNS) (Graybiel 1998; O’Donnell 1999), corticolimbic regions in the MOC network send approximately 30,000 afferents to each medium spiny neuron in the NASshell (more densely to the NASshell than to any other striat…”

“Behaviours are often linked together in ‘chunked’ sequences, so that the performance of one behaviour cues the next (Graybiel, 1998).”

“Some results have led to the suggestion of a sequential relationship, in which the PFC is involved in new learning and the basal ganglia are subsequently involved in consolidating familiar routines into automatic habit”

“…(1998) reported that, in rats, different DLS neurons fired in conjunction with simple grooming movements depending on whether those actions were performed in isolation or as part of a grooming sequence (see also Aldridge, Berridge, & Rosen, 2004; Graybiel,1995, 1998; Lee, Seitz, & Assad, 2006).”

“In our model, such neurodynamic sequences emerge from within basal forebrain and BG areas (Knowlton et al., 1996; Graybiel, 1998), and associated medial diencephalic and mesencephalic circuits, with parallel roles in learning and expression of motor habits and emotions (MacLean, 1990; Graybiel,…”

“This is confirmed by involvement of the striatum in the learning and production of habitual responses (Graybiel, 1998).”

“The slowness of movement (bradykinesia), thought (bradyphrenia), and mnemonic retrieval that characterize lesions of the basal ganglia suggest that the striatal deficits impair the initiation of behavior, and the ability to chunk information into manageable quanta (Graybiel 1998).”

“The human AST also receives convergent inputs from limbic-related cortical regions and therefore supports some integrative functions ascribed to the nucleus accumbens in rodents.(80,81) Thus, the AST, particularly the preDCA, is in a unique position to integrate information from multiple regions and to regulate circui…”

“In support of this hypothesis, task phase-formed cell assemblies have been described in the basal ganglia [78,79], basal forebrain [80], parietal cortex [81,82], and hippocampus [34,83].”

“The striatum is the major input nucleus of the basal ganglia, and as such it plays a crucial role in action control and action learning (Saint-Cyr et al., 1995; Graybiel,1998; Lalonde and Botez-Marquard, 1997; Yin and Knowlton, 2006).”

“1996; Finlay & Zigmond 1997; Spanagel & Weiss 1999), neuroplastic alterations spanning these striatal regions change the way ventral and dorsal compartments represent information and communicate with one another (Chambers et al. 2007; Graybiel 1998; Hyman & Malenka 2001).”

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“This area has been shown by a variety of studies to be an important component of the neural circuitry mediating habitual behavior [3,12, 22 ,24,35].”

“chunking as habits and routines form (Graybiel 1998; Graybiel 2008).”

“Multiple lines of evidence suggest that the basal ganglia—and specifically spiny projection neurons (SPNs) within its input nucleus, the striatum—play a key role in specifying both the contents and structure of behavior (Aldridge et al., 1993; Graybiel, 1998).”

“With chunking there can be an increase of coarticulation and reduced cognitive demands because less elements are organized for a given motor goal (Gobet et al., 2001; Graybiel, 1998).”

“An alternative approach to understanding action sequencing is to consider how actions are linked together in overlapping segments, sometimes termed chunking or chaining (Berstein 1967; Gobet et al. 2001; Graybiel 1998).”

“Others defend that action sequences could be represented in a hierarchical manner (Gallistel, 1980; Graybiel, 1998; Hikosaka et al., 2000; Lashley, 1951), where higher representations of the number and order of elements in a sequence may monitor and control execution of modules.”

“A related proposal for the role of the BG in motor sequence learning is that it associates multiple movements into groups or chunks [90,110,111].”

“First, learning of stimulus–action associations is dependent on the dorsal striatum (Graybiel 1998; Packard and Knowlton 2002; Robbins and Everitt 2002; White and McDonald 2002).”

“The basal ganglia operations characterized by Graybiel (1995, 1997, 1998) involve both motor pattern generators and cognitive pattern generators.”

“first stages but do not progress further, suggesting an impairment of long-term consolidation processes [12,14], which may rely on motivation and sensitivity to reinforcement.”

“Such an increase in neural noise in the basal ganglia likely impairs the facilitation and modulation of premotor regions that must act synergistically to generate accurate and well-timed movement ( Graybiel, 1998 , 2005 ; Leiguarda et al, 2000 ).”

“…of previous reports have described the appearance of uneven spacing in the timing of key-press transitions within motorsequence patterns—a phenomenon that has been termed " chunking " (Rosenbaum et al. 1983; Verwey and Dronkert 1996; Graybiel 1998; Sakai et al. 2003; Stöcker and Hoffmann 2004).”

“It debatable if pain is a learned behavior, but the BG may have a role in learning due to its involvement in habit and stimulus-response learning [119].”

“In the first, frontal cortex serves to uncover patterns in the environment that are subsequently consolidated in the basal ganglia (Graybiel, 1998).”

“In all three cases, patients were instructed to count the seconds.”

“…1993; Graybiel et al., 1994; Kimura et al., 1993; Marsden and Obeso, 1994; Middleton and Strick, 1994; Mirenowicz and Schultz, 1996), it is most unlikely that the cognitive “pattern generators” (Graybiel, 1997, 1998) that specify syntactic operations (Lieberman, 2000) are innately specified.”

“Implicit learning refers to reinforcement or habit learning [26,27], involving no verbalisation or meta-cognitive processing of the learned material.”

“In that way, the same basal ganglia mechanisms used for movement syntax may participate in sequential habits that result from learning [20,29,70-72].”

“Lesions in the dominant parietal areas sometimes cause deficits in temporal structuring of a motor sequence, called apraxia (Harrington and Haaland 1991a, 1992). The deficits may be the result of disruptions of chunk patterns in learned daily behaviors. Rushworth et al. (1998) have proposed a role of the left hemisphe…”

“Another proposed function of basal ganglia circuits, and the dorsal striatum in particular, is to encode short motor programs (so-called “chunking” of action repertoires), which can prevent excessive computational demands on cortical structures (Graybiel, 1998).”

“With continuing repetition these action elements can become linked together and run off together as a sequence, i.e. they can become chunked (Terrace, 1991; Graybiel, 1998).”

“2984" language="eng" relation="no"> The neostriatum is critical for the reinforcement-mediated acquisition and selection of adaptive behavioral response”

“The extended training and reinforcement establishes striatum-dependent learned movement sequences (Graybiel, 1998) that are prepotent within the task context, yet one of thesemust be suppressed on each trial.”

“Besides, our findings indicate that corticostriatal neuron activity alone or in conjunction with indirect connections between the cortex and striatum (for example, via functionally related thalamic nuclei) transmit a reliable depiction of cortical ensemble activity to the striatum, as postulated in theoretical models…”

“The ultimate output of the system is through the basal ganglia (striatum and pallidum), which governs the selection of one action amongst alternatives (Graybiel, 1998; Grillner et al., 2005; Kropotov and Etlinger, 1999; Mink and Thach, 1991).”

“The slowness of movement (bradykinesia), thought (bradyphrenia), and mnemonic retrieval that characterize lesions of the basal ganglia suggest that the striatal deficits impair the initiation of behavior, and the ability to chunk information into manageable quanta (Graybiel, 1998).”

“It may also be possible to reconcile the present findings suggesting that the dorsomedial striatum enhances behavioral flexibility with earlier theories of the striatum as a mediator of habit learning (Graybiel, 1998; Mishkin et al., 1984; Packard et al., 1989).”

“As organisms chunk an action sequence, the activity pattern of striatal cells changes so that most activity occurs at the beginning of the sequence, which is consistent with the striatum selecting the program as a whole (Graybiel, 1998; Barnes et al., 2005).”

“Most current functional interpretations of the basal ganglia focus on the theme of action gating or action selection (Bullock & Grossberg, 1988a; 1988b; 1991; Mink & Thach, 1993; Graybiel eta!., 1994; Hikosaka, 1994; Dominey ct. al., 1995; Berns & Sejnowski, 1998; Graybiel, 1998; Redgrave eta!., 1999).”

“There is consistent evidence that fast learning within a training session, as well as the gradual acquisition of a skill across repeated training sessions, is associated with significant changes in skill representation in various brain regions relevant to performance (Seitz et al., 1990; Jenkins et al., 1994; Elbert e…”

“Key structures in the implementation of automatic habit repertoires are the dorsolateral striatum and the premotor and motor cortices (Graybiel, 1998).”

“Sensorimotor aspects of the striatum are thought to contribute to facilitating automatic execution of motor acts or to implementing habits by building up individualmotor acts to coherent chunks of performance units (36).”

“The matrix consists of functionally distinct input modules (also known as the matrisomes) (Crittenden and Graybiel, 2011; Graybiel, 1998), subserving sensorimotor convergence and specialization (Graybiel, 1998; Mink, 2001).”