Biomedical subjects

Thomas R Shultz

Publications and source records attributed to Thomas R Shultz.

3 recordsLinked to original sources

PubMed2007

Rule following and rule use in the balance-scale task.

Quinlan et al. [Quinlan, p., van der Mass, H., Jansen, B., Booij, O., & Rendell, M. (this issue). Re-thinking stages of cognitive development: An appraisal of connectionist models of the balance scale task. Cognition, doi:10.1016/j.cognition.2006.02.004] use Latent Class Analysis (LCA) to criticize a connectionist model of development on the balance-scale task, arguing that LCA shows that this model fails to capture a torque rule and exhibits rules that children do not. In this rejoinder we focus on the latter problem, noting the tendency of LCA to find small, unreliable, and difficult-to-interpret classes. This tendency is documented in network and synthetic simulations and in psychological research, and statistical reasons for finding such unreliable classes are discussed. We recommend that LCA should be used with care, and argue that its small and unreliable classes should be discounted. Further, we note that a preoccupation with diagnosing rules ignores important phenomena that rules do not account for. Finally, we conjecture that simple extensions of the network model should be able to achieve torque-rule performance.

Cognition↗

PubMed2006

Modeling developmental cognitive neuroscience.

In the past few years connectionist models have greatly contributed to formulating theories of cognitive development. Some of these models follow the approach of developmental cognitive neuroscience in exploring interactions between brain development and cognitive development by integrating structural change into learning. We describe two classes of these models. The first focuses on experience-dependent structural elaboration within a brain region by adding or deleting units and connections during learning. The second models the gradual integration of different brain areas based on combinations of experience-dependent and maturational factors. These models provide new theories of the mechanisms of cognitive change in various domains and they offer an integrated framework to study normal and abnormal development, and normal and impaired adult processing.

Algorithms↗

PubMed2006

Preschoolers out of adults: discriminative learning with a cognitive load.

This paper explores novel predictions from the spontaneous overtraining interpretation of human discrimination shift learning (Sirois & Shultz, 1998a). Results from six experiments where adults perform a discrimination shift task with or without a cognitive distractor are reported. In three experiments with a concurrent distractor task (Experiments 1A, 2A, and 3A), performance of adults is comparable to what would be expected from preschoolers performing only the learning task. These adults show no dimensional transfer from initial learning, unless new attributes are introduced in shift learning. On the same tasks without a cognitive load (Experiments 1B, 2B, and 3B), performance is typical of normal adults. The discussion focuses on the relative ability of competing theoretical models (i.e., levels of processing, attentional mediation, and perceptual differentiation) to account for these data.

Adult↗