Distortions in time perception and timed performance are presented by a number of different neurological and psychiatric conditions (e.g. Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder and autism). As a consequence, the primary focus of this review is on factors that define or produce systematic changes in the attention, clock, memory and decision stages of temporal processing as originally defined by Scalar Expectancy Theory. These findings are used to evaluate the Striatal Beat Frequency Theory, which is a neurobiological model of interval timing based upon the coincidence detection of oscillatory processes in corticostriatal circuits that can be mapped onto the stages of information processing proposed by Scalar Timing Theory.

Humans share with other animals an ability to measure the passage of physical time and subjectively experience a sense of time passing. Subjective time has hallmark qualities, akin to other senses, which can be accounted for by formal, psychological, and neurobiological models of the internal clock. These include first-order principles, such as changes in clock speed and how temporal memories are stored, and second-order principles, including timescale invariance, multisensory integration, rhythmical structure, and attentional time-sharing. Within these principles there are both typical individual differences--influences of emotionality, thought speed, and psychoactive drugs--and atypical differences in individuals affected with certain clinical disorders (e.g., autism, Parkinson's disease, and schizophrenia). This review summarizes recent behavioral and neurobiological findings and provides a theoretical framework for considering how changes in the properties of the internal clock impact time perception and other psychological domains.

Neurocognitive assessment in individuals with intellectual disabilities requires a well-validated test battery. To meet this need, the Arizona Cognitive Test Battery (ACTB) has been developed specifically to assess the cognitive phenotype in Down syndrome (DS). The ACTB includes neuropsychological assessments chosen to 1) assess a range of skills, 2) be non-verbal so as to not confound the neuropsychological assessment with language demands, 3) have distributional properties appropriate for research studies to identify genetic modifiers of variation, 4) show sensitivity to within and between sample differences, 5) have specific correlates with brain function, and 6) be applicable to a wide age range and across contexts. The ACTB includes tests of general cognitive ability and prefrontal, hippocampal and cerebellar function. These tasks were drawn from the Cambridge Neuropsychological Testing Automated Battery (CANTAB) and other established paradigms. Alongside the cognitive testing battery we administered benchmark and parent-report assessments of cognition and behavior. Individuals with DS (n = 74, ages 7–38 years) and mental age (MA) matched controls (n = 50, ages 3–8 years) were tested across 3 sites. A subsample of these groups were used for between-group comparisons, including 55 individuals with DS and 36 mental age matched controls. The ACTB allows for low floor performance levels and participant loss. Floor effects were greater in younger children. Individuals with DS were impaired on a number ACTB tests in comparison to a MA-matched sample, with some areas of spared ability, particularly on tests requiring extensive motor coordination. Battery measures correlated with parent report of behavior and development. The ACTB provided consistent results across contexts, including home vs. lab visits, cross-site, and among individuals with a wide range of socio-economic backgrounds and differences in ethnicity. The ACTB will be useful in a range of outcome studies, including clinical trials and the identification of important genetic components of cognitive disability.

Perception of time, in the seconds to minutes range, is not well characterized in autism. The required interval timing system (ITS) develops at the same stages during infancy as communication, social reciprocity, and other cognitive and behavioral functions. The authors used two versions of a temporal bisection procedure to study the perception of duration in individuals with autism and observed quantifiable differences and characteristic patterns in participants’ timing functions. Measures of timing performance correlated with certain autism diagnostic and intelligence scores, and parents described individuals with autism as having a poor sense of time. The authors modeled the data to provide a relative assessment of ITS function in these individuals. The implications of these results for the understanding of autism are discussed.

In reinforcer-selective transfer, Pavlovian stimuli that are predictive of specific outcomes bias performance toward responses associated with those outcomes. Although this phenomenon has been extensively examined in rodents, recent assessments have extended to humans. Using a stock market paradigm adults were trained to associate particular symbols and responses with particular currencies. During the first test, individuals showed a preference for responding on actions associated with the same outcome as that predicted by the presented stimulus (i.e., a reinforcer-selective transfer effect). In the second test of the experiment, one of the currencies was devalued. We found it notable that this served to reduce responses to those stimuli associated with the devalued currency. This finding is in contrast to that typically observed in rodent studies, and suggests that participants in this task represented the sensory features that differentiate the reinforcers and their value during reinforcer-selective transfer. These results are discussed in terms of implications for understanding associative learning processes in humans and the ability of reward-paired cues to direct adaptive and maladaptive behavior.

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Estimations of time and number share many similarities in both non-humans and man. The primary focus of this review is on the development of time and number sense across infancy and childhood, and neuropsychological findings as they relate to time and number discrimination in infants and adults. Discussion of these findings is couched within a mode-control model of timing and counting which assumes time and number share a common magnitude representation system. A basic sense of time and number likely serves as the foundation for advanced numerical and temporal competence, and aspects of higher cognition—this will be discussed as it relates to typical childhood, and certain developmental disorders, including autism spectrum disorder. Directions for future research in the developmental neuroscience of time and number (NEUTIN) will also be highlighted.

The current study examined whether stimuli of different preference levels would be associated with different amounts of work maintained by the stimuli, as determined through progressive-ratio schedule break points. Using a paired-choice preference assessment, stimuli were classified as high, moderate, or low preference for 4 individuals with developmental disabilities. The stimuli were then tested three times each using a progressive-ratio schedule (step size of 1; the break-point criterion was 1 min). In 10 of 12 possible comparisons, higher preference stimuli produced larger break points than did lower preference stimuli.