interactive metronome: whats happening under the hood

The Synchronized Metronome Tapping (SMT) Effect: Preliminary thoughts on “what’s happening under the hood”

Kevin McGrew, Ph.D.

Institute for Applied Psychometrics LLC

(www.iapsych.com)

Select IM Intervention Performance Studies

Sports: Tennis performance

•10-week intervention study significantly improved the tennis performance of 8-10 year olds (Zachopoulou, Mantis & Psalti, In Press).

Sports: Golf performance

•After 10 hours of timing training experimental participants significantly improved the accuracy of their golf swing relative to control participants (Libkuman & Otani, 2002).


Behavior: Children with ADHD

•Boys with attention-deficit / hyperactivity disorder (ADHD)

•15 hours of training

•Experimental participants displayed significant improvements in attention, motor control, language processing, reading, and parent report of regulation of aggressive behavior (Shaffer, et al., 2001).


School Achievement

•High school IM intervention produced significant improvement in reading recognition and fluency and math (Lazarus & Taub, 2005; Taub, McGrew & Lazarus, 2005)

•Elementary school IM intervention produced significant improvements in basic reading skills and speed of processing of basic lexical information [RAN] (Taub, McGrew & Keith, 2005)

How can such an apparently simple intervention produce improvements across such diverse human performance domains?

•"We believe timing is the foundation for learning and memory," Meck said in an interview. He suggests that defective timing mechanisms may underlie some learning disabilities and may contribute to dyslexia.”

•“It's hard to find any complex behavioral process that timing isn't involved in”

•"These studies demonstrate for the first time the importance of frontal-striatal loops in people timing short intervals,"

•fMRI methods found that “the frontal cortex and the striatum, a portion of the brain previously thought to be involved only with motor skills” were the most active parts of the brain during time interval estimation

Duke Researcher’s Meck & Buhusi (2005)

Timing across different timescales (compilation of data from various human and animal studies – Bushi & Meck, 2005)

Importance of interval timing (Bushi & Meck,

2005)

•Time and space are the fundamental dimensions of our life/existence

•To deal with time, organisms have developed multiple systems that are active over more than 10 orders of magnitude with various degrees of precision (see figure)

SMT (IM) would be operating

primarily at interval and millisecond

timing levels

A domain-generalcognitive mechanism?

A number of domain (subject)-specific cognitive mechanisms?

OR….

A domain-general

cognitive mechanism?

•There is a long-standing tradition within psychological research to search for general principles or cognitive mechanisms that can be used to address all aspects of behavior and cognition.

•Not tied to any specific content or domain.

•An underlying mechanism that can be applied to a wide range of novel problems and domains of performance

•“Jack-of-all-trades” mechanisms (Chiappe & McDonald,2005)

•These are the mechanisms that may be captured by the notion of “g” (general intelligence), and include such cognitive mechanisms as executive function and working memory (Chiappe & McDonald, 2005)

g (general intelligence)

• Searching for the “essence” of g has been the holy grail In intelligence research

•g is a domain general mechanism as it is not specific to any particular domain of knowledge or mental skill and appears to be independent of cultural context (Gottfrredson, 1998)

•Biological correlates of g include brain size, speed of nerve conduction, energy qualities of brain waves, etc.

•Research has suggested that people differ in g due to some form of differences in speed/efficiency of neural processing (neural efficiency/oscillation hypothesis)

•Most prominent paradigm for investigating g has been the use of elementary cognitive tasks (ECTs) (see Jensen)

•Reaction time (RT) measures (Hick paradigm; Hicks law)

•Decision time (DT)•Movement time (MT)•Metric is in milliseconds•No obvious intellectual content

•RT measures are believed to measure the speed with which the brain apprehends, integrates and evaluates information (Gottfredson, 1998; Hunt, 1999; Jensen, 1998a; Sternberg & Kaufman, 1998).

•Search continues for the underlying biological determinants


Is there an accepted, empirically validated theory or model to explain mental time-keeping?

Yes

Pacemaker-Accumulator Model basedOn Scalar Timing/Expectancy Theory

(Church, 1984; Gibbon et al., 1984; Meck, 1983)

The most prominent theory/model of time/temporal estimation

Time duration judgments are performed by a modular information processing system composed of:

•Clock

•Memory

•Decision processes

The “clock”level

Regularly generates or emits

neural ticks or pulses

“gaiting” switch from pacemaker

to accumular

Accumulates ticks/pulses that correspond to

duration (neural counting)

The “memory”level

“Raw” representation of stimulus duration transferred to short-term or working memory

Includes “important times” or “standards” appropriate for task

The “decision”level

Comparison made between contents of reference memory (the standard) and working memory (are they “close” ?).

Relies on a comparator that determines a response on the basis of a decision rule which involves a comparison between a value in the accumulator or working memory corresponding to the current duration with a value from reference memory

Pacemaker-Accumulator Model basedOn Scalar Timing/Expectancy Theory

(Church, 1984; Gibbon et al., 1984; Meck, 1983)

•Note presence of working memory (in some models accumulator and working memory are combined)

•Controlled executive attention crucial at all stages of information processing timing model

•Note importance of types of executive function skills (e.g., monitoring, comparing, etc.)


Performance on temporal information processing as anindex of general intelligence

Rammsayer & Brandler (2006, in press)

•Analyses suggested a unitary timing mechanism, referred to as temporal g.

•Performance on temporal information processing provided a more valid predictor of psychometric g than traditional reaction time measures

•Findings suggest that temporal resolution capacity of the brain (as assessed with psychophysical temporal tasks) reflects aspects of neural efficiency associated with general intelligence.

Rammsayer & Brandler (2006, in press)

Temporal g ?

•The notion of an internal master clock represents an alternative metaphor to account for the relationship between efficiency and speed of information processing and psychometric g. (Rammsayer & Brandler, 2006, in press)

•The concept of a hypothetical master clock has been introduced by Surwillo (1968).

•Proposed an internal clock mechanism in the central nervous system for coordination of different neural activities.

•Burle and Bonnet (1997, 1999) provided additional converging experimental evidence for the existence of some kind of master clock in the human information processing

Temporal g ?

•Temporal information processing models (Creelman, 1962; Gibbon, 1991; Rammsayer & Ulrich, 2001; Treisman et al., 1990; see Grondin, 2001 for review) are based on the central assumption of neural oscilliations (note – same central feature of Jensen’s neural efficiency theory of g) as a major determinant of timing performance.

•The higher the frequency of neural oscillations the finer the temporal resolution of the internal clock = greater timing accuracy (Rammsayer & Brandler; 2006, in press)

Temporal g ?

•Research has suggested that this internal master clock can account for performance across four major types of elementary timing experiences (Rammsayer & Brandler, 2006, in press)

•Interval timing

•Rhythm perception

•Temporal-order judgment (TOJ)

•Simultaneity and successiveness

Temporal g ?

According to the master internal clock theory:

•Higher clock rate should not only enable an individual to perform a specific sequence of mental operations faster

•Higher clock rate decreases the probability of occurrence of interfering incidents.

•This results in superior performance in cognitive tasks as well as in basic information processing skills.

Temporal g ?

What are the possible underlying brain structures or functions involved?

A very simplified review

Motor cortex areas

Select information (Hale & Fiorrello, 2004; Jenkins et al, 1994; Paretz & Zatorre, 2005):

•Supplementary motor area important for bimanual coordination and is more active during previously learned or routinized motor patterns

•Premotor cortex active when learning new/novel motor sequences. Associated with imagined movements (Diamond, 2003).

•Primary motor cortex responsible for directing movements in response to the environment

Cerebellum

•Associated with body position (balance, posture, eye movement) (Hale & Fiorello, 2004)

•Involved in coordinated motor skill acquisition (Debaere et al., 2001)

•Seems to be involved in timing, learning, memory and coordinating cognitive functions (Ivry, 1993; Janata & Grafton, 2003; Nobre & O’Reilly, 2004; Peretz & Zatorre, 2005; Rapoport et al., 2000)

Frontal lobe

Executive functions•Attention•Planning•Strategizing•Organizing•Flexibility•Monitoring•Evaluation•Change

Frontal lobe is responsible for action(Hale & Fiorrello, 2004; Duncan et al., 1995; Duncan et al., 1996)

Research has implicated the frontal lobes as the possible location of a “mental time-keeper” (Meck, 1983; Meck et al., Nobre & O’Reilly, 20041984; Papagno et al., 2004)

Prefrontal cortex

The “brain manager” or “boss” (Hale & Fiorrello, 2004; Luria,1973)

Prefrontal cortex

Has high degree of interconnectivity (with other parts of the brain)

•This allows the prefrontal cortex to integrate input from many sources in order to implement more abstract behaviors

Is uniquely oriented to time.

(Huey et al., 2006)

Dorsolateral prefrontal cortex (DLPFC)

•Highest cortical area responsible for motor planning, organization and regulation (Hale & Fiorello, 2004)

•Associated with executive functions

•Intimately involved in planning, organizing, strategizing, initiating, monitoring, evaluating, modifying, changing, and shifting (requiring flexibility) (Hale & Fiorello, 2001)

•Executive attention (Kane & Engle, 2002; Rueda et al., 2005)

•DLPFC has rich connections with almost every area in the cortex, and either directly or indirectly with almost every subcortical area, especially the basal ganglia and limbic system

•Involved in motor function (posture, tone, motor activity,response coordination, sequencing, control of ongoing movement), voluntary events, attention, working memory, executive functions) (Cassidy et al., 2002; Hale & Fiorello, 2004; Middleton & Strick, 2000).

•Has rich interconnections between cortical and subcortical structures, including the cerebellum

•Significantly involved in motor planning, sensory performance and sensorimotor integration (Diamond, 2003)

Basal ganglia

A group of nuclei deep in the cerebral hemispheres involved in the generation of goal-directed voluntary movement (VandenBos, 2006)

•Converging evidence has implicated the role of the basal ganglia, operating via the frontal-striatal loop, in mental timing functions (Janata & Grafton, 2003; Nobre & O’Reilly, 2004; Peretz & Zatorre, 2005)

Basal ganglia and frontal-striatal loop

Basal ganglia and frontal-striatal loop serve like conductor: Monitors resonance/oscillations of different

brain structures and integrates them together

“Big five” reciprocal frontal-subcortical circuits (loops)

•There are at least five big loops/circuits involved in the highest levels of self-management (Lichter & Cummings, 2001)

•These “loops” give rise to the complexity of goal-directed behavior

•All five circuits (motor, oculomotor, dorsolateral prefrontal, anterior cingulate) are related to the frontal lobe, basal ganglia, and thalamus (Hale & Fiorello, 2004)

•The frontal-striatal loop has been associated with timing related functions (Nobre & O’Reilly, 2004)

Use measures from contemporary:

Intelligence theory

•Cattell-Horn-Carroll (CHC) theory of cognitive abilities

Neuropsychological theory

•Executive functioning•Working memory•Controlled executive attention

Can we measure the cognitive changes in these brain-based mechanisms ?

The executive function is a theorized cognitive system (cluster of skills) that controls and manages other cognitive processes (Baddeley & Hitch, 1974).

Executive functions include:

•Attention•Planning•Strategizing•Organizing•Flexibility•Monitoring•Evaluation•Change

Processes involved in mentaltiming are also thought to be components of EF (Welsh, 2001)

Has also been called the Supervisory Attention System (SAS; Norman & Shallice, 1986) and Executive Control (Posner and DiGirolamo (2000)

Executive functions/functioning (EF)

Executive functions/functioning are typically specified as a critical component of models of

working memory

Executive function needs working memory to carry out it’s various functions.

•Executive function and working memory can be considered domain-general cognitive mechanisms (Chiappe & McDonald, 2005)

•Working memory is the process of temporarily storing relevant information and performing operations for problem solving/performance

•Working memory is a resource-limited system that requires efficient management and sharing of resources for competent task performance

•Central to executive function and working memory is the construct of executive controlled attention (Barrett et al., 2004; Conway et al., 2003; Conway et al., 2005; Engle, 2002; Engle et al,, 1999; Kane et al., 2001)

Controlled Executive Attention (domain-general mechanism) model of working memory (Kane,

Engle, Conway model)

Working memory as a multi-component system responsible for active maintenance of information in the face of ongoing processing and/or distraction

Working memory capacity is not directly about memory—its about using attention to maintain or suppress information

Greater working memory capacity does mean that more information can be maintained as active, but this is a result of greater ability to control attention, not a larger memory store

“There is a large and consistent body of research to indicate that thecapability to control attention (especially in contexts in whichthere are competing demands) is a major determiner of an individual’sperformance on complex working memory tasks (Engle,2002; Kane, Bleckley, Conway, & Engle, 2001).

[Note. g = working memory capacity is an active and popular research hypothesis in the field of intelligence]

The ability to control attention is central to dual-process models of cognition (automatic vs controlled processing) (Barrett et al., 2004).

•Managing attention is central to controlled cognitive processing

Controlled attention is critical to goal management (Engle et al., 1999; Kane et al., 2001; Lustig et al., 2001).

•The mechanisms of controlled attention are limited capacity mechanisms responsible for activating relevant representations and keeping them in an active state while inhibiting irrelevant ones.

Studies have suggested that attention plays a pivotal role in mental time estimation (Brown & Boltz, 2002; Papagno et al., 2004)

Recent studies have shown that working memory and interval timing rely on the same anatomical structures (Baudouin et al., 2006; Lustig et al., 2005).

Controlled Executive Attention Model of Working Memory

Attention is one of the most important psychological processesthat regulate the experience of time (Brown & Boltz, 2002).

Radically different impressions of duration can result from different degrees to which attention is directed toward temporal events.

•For example, attentiveness to the passage of an interval makes time appear to flow at a relatively slow rate, an experience termed the watched pot phenomenon (Cahoon & Edmonds, 1980).

•In contrast, inattentiveness to time, as in the case of being absorbed in some activity, causes time to flow at a faster rate (an effect giving rise to the saying, Time flies when you’re having fun).


Controlled executive attention is mediated by portions of the pre-frontal cortex (the brain’s manager/boss), and the dorsolateral pre-frontal cortex circuitry in particular (Kane & Engle, 2002; LaBerge, 2000; Posner & Peterson, 1990)


The PFC has been likened to a switch operator in a railway system (Miller & Cohen; 2001.) [Also see “task switching” attention research summarized by Pashler et al., 2001)

“If several trains (different systems of representations or pathways) use the same bit of track to get where they are going (i.e., use the same output pathways when competing for expression in behavior), then a coordinator is needed to guide them safely to their destinations. Some trains must be stopped at the station; others may be stopped mid-route. Some will be allowed to go, and still others asked to speed up. The fastest train will use the track first (the system with the strongest activation pattern is expressed). The resource limitations of controlled attention are thought to reflect the properties of PFC function (Miller & Cohen, 2001) such that the fundamental computational properties of the PFC are likely related to the ability to control the trains.” (Barrett et al., 2004)

More on the Prefrontal Cortex (PFC) and Executive Attention

A possible lay-person term for

controlled executive attention is focus

•“the concentration of attention or energy on something”

•“concentrate: direct one's

attention on something”


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What are some other everyday examples of automaticcognitive processing (cognitive routines “automatized”)?



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An example of “controlled cognitive processing”



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SMT (e.g. IM) is hypothesized to increase the efficiencyof the “information processing loop” – increased “cognitiveefficiency” in the information processing bottleneck

Summary Comments

What’s going on “under the hood?”

•Increased efficiency of working memory

•Increased ability to sustain and selectively divide attention for longer periods of time (executive/controlled attention)?

•Increased ability to filter or screen out distractions (increased selective attention)?

•Increased ability to inhibit impulsive responding (decreased disinhibition)?

•Increased ability to self-regulate/monitor mental operations (metacognition)?

•Increased efficiency of internal master clock (higher clock rate)

Hypothesized changes in specific cognitive efficiency/executive

functioning: Increased “focus” or “cognitive efficiency”

Other possible hypothesis

Anecdotal reports from treatment subjects suggests possible improvements in non-cognitive variables that have been demonstrated to positively impact school learning

Conative variables (work of Richard Snow et al.)

•Increased self-efficacy

•Confidence in ability to organize, execute, and regulate performance in order to solve problem or perform a task at a designated level of skill and ability

What’s going on “under the hood?”

interactive metronome: whats happening under the hood

Technology

defective timing mechanisms

tennis performance of8

simple intervention

timing isnt

figure smt im

animal studies bushi

fluencyandmathlazarus

mcgrew lazarus