Teresa McCormack

Developmental changes in time estimation: comparing childhood and old age.

Participants from ages 5 to 99 years completed 2 time estimation tasks: a temporal generalization task and a temporal bisection task. Developmental differences in overall levels of performance were found at both ends of the life span and were more marked on the generalization task than the bisection task. Older adults and children performed at lower levels than young adults, but there were also qualitative differences in the patterns of errors made by the older adults and the children. To capture these findings, the authors propose a new developmental model of temporal generalization and bisection. The model assumes developmental changes across the life span in the noisiness of initial perceptual encoding and across childhood in the extent to which long-term memory of time intervals is distorted.

Searching and Planning: Young Children’s Reasoning About Past and Future Event Sequences

Six experiments examined childrens ability to make inferences using temporal order information. Children completed versions of a task involving a toy zoo; one version required reasoning about past events (search task) and the other required reasoning about future events (planning task). Children younger than 5 years failed both the search and the planning tasks, whereas 5-year-olds passed both (Experiments 1 and 2). However, when the number of events in the sequence was reduced (Experiment 3), 4-year-olds were successful on the search task but not the planning task. Planning difficulties persisted even when relevant cues were provided (Experiments 4 and 5). Experiment 6 showed that improved performance on the search task found in Experiment 3 was not due to the removal of response ambiguity.

Identification, of tone duration, line length, and letter position : an experimental approach to timing and working memory deficits in schizophrenia

Patients with schizophrenia display numerous cognitive deficits, including problems in working memory, time estimation, and absolute identification of stimuli. Research in these fields has traditionally been conducted independently. We examined these cognitive processes using tasks that are structurally similar and that yield rich error data. Relative to healthy control participants (n = 20), patients with schizophrenia (n = 20) were impaired on a duration identification task and a probed-recall memory task but not on a line-length identification task. These findings do not support the notion of a global impairment in absolute identification in schizophrenia. However, the authors suggest that some aspect of temporal information processing is indeed disturbed in schizophrenia.

Identification and Bisection of Temporal Durations and Tone Frequencies: Common Models for Temporal and Nontemporal Stimuli.

Two experiments examined identification and bisection of tones varying in temporal duration (Experiment 1) or frequency (Experiment 2). Absolute identification of both durations and frequencies was influenced by prior stimuli and by stimulus distribution. Stimulus distribution influenced bisection for both stimulus types consistently, with more positively skewed distributions producing lower bisection points. The effect of distribution was greater when the ratio of the largest to smallest stimulus magnitude was greater. A simple mathematical model, temporal range frequency theory, was applied. It is concluded that (a) similar principles describe identification of temporal durations and other stimulus dimensions and (b) temporal bisection point shifts can be understood in terms of psychophysical principles independently developed in nontemporal domains, such as A. Parduccis (1965) range frequency theory.

Distinctiveness models of memory and absolute identification: Evidence for local,not global, effects

Many models of memory assume that the probability of remembering an item is related to how distinctive that item is relative to all the other items in the set, with no distinction made between the contributions of near or far items. These “global” distinctiveness models do well in accounting for the ubiquitous serial position effects observed in numerous memory paradigms, including absolute identification. Here, we provide experimental confirmation of Bowers (1971) suggestion that, contrary to a fundamental prediction of global distinctiveness models, midseries items can be more discriminable than their immediate neighbours. We show that such data are consistent with a revised distinctiveness account in which the factor affecting discrimination performance is primarily the distinctiveness of an item relative to its close neighbours.

The development of regret

In two experiments, 4- to 9-year-olds played a game in which they selected one of two boxes to win a prize. On regret trials the unchosen box contained a better prize than the prize children actually won, and on baseline trials the other box contained a prize of the same value. Children rated their feelings about their prize before and after seeing what they could have won if they had chosen the other box and were asked to provide an explanation if their feelings had changed. Patterns of responding suggested that regret was experienced by 6 or 7 years of age; children of this age could also explain why they felt worse in regret trials by referring to the counterfactual situation in which the prize was better. No evidence of regret was found in 4- and 5-year-olds. Additional findings suggested that by 6 or 7 years, childrens emotions were determined by a consideration of two different counterfactual scenarios.

Episodic temporal generalization : a developmental study

Groups of 5-year-olds, 10-year-olds, and adults completed either an episodic temporal generalization task, in which no stimuli were repeated, or a repeated standard temporal generalization task, in which there was a fixed standard that was repeated on every trial. Significant developmental improvements were found on both tasks. In both tasks, gradients of performance over two different stimulus ranges superimposed well when plotted on the same relative scale. Performance was similar for the adults and 10-year-olds across tasks, but the 5-year-olds performed better on the repeated standard task. These findings suggest that perceptual processes are a source of scalar variability in timing, and that there are developmental changes in levels of such variability.

Children's reasoning about the causal significance of the temporal order of events

Four experiments examined childrens ability to reason about the causal significance of the order in which 2 events occurred (the pressing of buttons on a mechanically operated box). In Study 1, 4-year-olds were unable to make the relevant inferences, whereas 5-year-olds were successful on one version of the task. In Study 2, 3-year-olds were successful on a simplified version of the task in which they were able to observe the events although not their consequences. Study 3 found that older children had difficulties with the original task even when provided with cues to attend to order information. However, 5-year-olds performed successfully in Study 4, in which the causally relevant event was made more salient.

Tool Use and Causal Cognition

1. Tool Use and Causal Cognition: An Introduction 2. A Philosopher Looks at Tool Use and Causal Understanding 3. The Development of Tool Use Early in Life 4. Through a Floppy Tool Darkly: Toward a Conceptual Overthrow of Animal Alchemy 5. Causal Knowledge in Corvids, Primates and Children: More Than Meets the Eye? 6. The Evolutionary Origins of Causal Cognition: Learning and Using Causal Structures 7. Tool Use, Planning, and Future Thinking in Children and Animals 8. Representing Causality 9. Why Do Language and Tool Use Both Count as Manifestations of Intelligence? 10. Effects of brain damage on human tool use 11. Human tool-use: a causal role in plasticity of bodily and spatial representations 12. Tool-use and the representation of peripersonal space in humans

Cue competition effects and young children's causal and counterfactual inferences

The authors examined cue competition effects in young children using the blicket detector paradigm, in which objects are placed either singly or in pairs on a novel machine and children must judge which objects have the causal power to make the machine work. Cue competition effects were found in a 5- to 6-year-old group but not in a 4-year-old group. Equivalent levels of forward and backward blocking were found in the former group. Childrens counterfactual judgments were subsequently examined by asking whether or not the machine would have gone off in the absence of 1 of 2 objects that had been placed on it as a pair. Cue competition effects were demonstrated only in 5- to 6-year-olds using this mode of assessing causal reasoning.