Biomedical subjects

Philip A Allen

Publications and source records attributed to Philip A Allen.

5 recordsLinked to original sources

PubMed2002

Ideomotor compatibility in the psychological refractory period effect: 29 years of oversimplification.

Four experiments examined whether the psychological refractory period (PRP) effect can be eliminated with ideomotor compatible (IM) but not stimulus-response compatible (SR) tasks, as reported by A. G. Greenwald and H. G. Shulman (1973). Their tasks were used: a left or right movement to a left- or right-pointing arrow (IM) or to the word left or right (SR) for Task 1; saying "A" or "B" (IM) or "1" or "2" (SR) to an auditory A or B for Task 2. The stimulus onset asynchronies were 0, 100, 200, 300, 500, and 1,000 ms in Experiment 1, and only 0, 100, 200, and 1,000 ms in Experiments 2-4. The arrow was in the center of the screen in Experiments 1-3 and to the left or right in Experiment 4. As in Greenwald and Shulman's Experiment 2, the instructions stated that most often the 2 stimuli would be presented simultaneously. A PRP effect was obtained in all conditions, most likely because response-selection decisions are required even for IM tasks.

Acoustic Stimulation↗

PubMed2002

Age differences in overlapping-task performance: evidence for efficient parallel processing in older adults.

Two psychological refractory period (PRP) experiments were conducted to examine overlapping processing in younger and older adults. A shape discrimination task (triangle or rectangle) for Task 1 (T1) and a lexical-decision task (word or nonword) for Task 2 (T2) were used. PRP effects, response time for T2 increasing as stimulus onset synchrony (SOA) decreased, were obtained for both age groups. The effect of word frequency on T2 was smaller at the short SOA than at the long SOA, reflecting slack effects, which were larger for older than younger adults in both experiments. These results suggest that older adults can perform lexical access of T2 in parallel with the processing of T1 at least as efficiently as younger adults.

Adolescent↗

PubMed2002

Differential age effects in semantic and episodic memory.

Results from 4 experimental tasks and 8 data sets (the 4 tasks involved either multiple sessions or different stimuli) as well as a vocabulary test conducted on the same 80 participants (40 younger and 40 older adults) are reported. The authors employed 2 semantic memory tasks (lexical decision and multiplication verification) using data from 2 sessions (for a total of 4 semantic data sets) and 2 episodic memory tasks (hybrid visual search and memory search with digits and with words as stimuli). Factor analyses using slope and intercept data from the 8 experimental data sets indicated the presence of 3 latent factors: a single intercept factor for both episodic and semantic tasks and separate slope factors for episodic and semantic tasks. A structural equation model with paths from age to 3 different 1st-order latent factors (episodic central processes, semantic central processes, and combined episodic and semantic peripheral processes) fit better than general factor models. These data are consistent with a theoretical framework in which there are age-related dissociations between peripheral and central processes across semantic and episodic memory.

Adolescent↗

PubMed2002

Differential age effects for case and hue mixing in visual word recognition.

The authors compare older adults' lexical-decision data with younger adults' data reported in P. Allen, A. F. Smith, et al. (2002). On the basis of their work, it was proposed that consistent-case wordswould be processed by the faster holistic (magnodominated) stream, but that mixed-case words would be processed by the slower analytic (interblob-dominated or blob-dominated) steams. Hue mixing was predicted to have no effect on consistent-case performance, but mixed-hue/mixed-case words were predicted to be recognized faster than monochrome/mixed-case words. Younger adults showed the predicted results, but older adults did not. These results suggest that holistic central processes are maintained, but that older adults exhibited an analytic decrement

Adolescent↗

PubMedDate not supplied

Differential age effects in semantic and episodic memory, Part II: Slope and intercept analyses.

This study tested for dissociations between age-related slowing in peripheral and central processes across semantic and episodic memory tasks. We report the mixed-model analysis of variance (ANOVA) results using reaction time (RT), error, and data from four different experimental tasks and eight data sets (the four tasks involved either multiple sessions or different stimuli) conducted on the same 80 participants (40 younger and 40 older adults). An earlier paper (Allen, Sliwinski, Bowie, & Madden, in press) reported the factor analysis and structural equation modeling results of this study. We employed two semantic memory tasks (lexical decision and multiplication verification) using data from two different sessions (for a total of four semantic data sets), and two episodic memory tasks (hybrid visual search and memory search with digits and with words as stimuli). For RT analyses, we found Age x Task interactions for all four episodic memory data sets, but no Age x Task interactions for the four semantic memory data sets. Also, the intercept (assumed to index peripheral processes) and slope (assumed to index central processes) analyses demonstrated that older adults (relative to younger adults) showed both intercept and slope decrements for episodic memory tasks, but only intercept decrements for semantic memory tasks. These data are consistent with a theoretical framework in which there are age-related dissociations between peripheral and central processes across semantic and episodic memory.

Adolescent↗