Biomedical subjects

Lawrence R Gottlob

Publications and source records attributed to Lawrence R Gottlob.

8 recordsLinked to original sources

PubMed2007

Aging and capacity in the same-different judgment.

The same-different judgment was used in two experiments to investigate age-group differences in visual processing. Two targets next to fixation were presented; the targets on one-half of the trials were the same, and on the other half of the trials, the targets differed by color, shape, or color and shape (redundant). Response times were lower for redundant trials than for color-only and shape-only trials; this redundancy gain was greater for older observers than for young observers. Capacity measures based on the integrated hazard functions indicated that young adults, but not older adults, experienced a slowing of processing (reduction of capacity) in the redundant condition. These capacity measures may provide a method for interpreting age-group effects in the presence of overall response-time differences.

Adolescent↗

PubMed2006

Alcohol effects on inhibitory control of attention: distinguishing between intentional and automatic mechanisms.

RATIONALE: Recent research has begun to explore the possibility that inhibitory mechanisms of selective attention are particularly susceptible to the impairing effects of moderate doses of alcohol. However, literature also suggests that automatic processes might be more resistant to this impairing effect than controlled processes. OBJECTIVE: The present study used a delayed ocular response task and a saccadic interference task to examine the effects of alcohol on both intentionally controlled and automatic inhibitory influences on selective attention. MATERIALS AND METHODS: Twelve healthy adults performed both tasks under three doses of alcohol (0.0, 0.45, and 0.65 g/kg). RESULTS: The results showed that alcohol reduced intentional inhibitory control over selective attention but had no effect on automatic inhibitory influences. CONCLUSION: The present investigation marks the first effort to directly compare alcohol effects on automatic and intentional inhibitory mechanisms of visual attention. The results suggest that attentional processes dependent on intentional inhibitory control may be more susceptible to the impairing effects of a moderate dose of alcohol than processes dependent on automatic inhibition.

Administration, Oral↗

PubMed2006

Age-related deficits in guided search using cues.

The ability of young and older adults to engage in guided conjunction search was tested in 2 experiments. In the cued condition, a picture of the target was presented before the search. In the noncued condition, there was no picture of the target. In Experiment 1, the cue was presented for 200 ms; the magnitude of the cuing effect (noncued response time--cued response time) was greater for the young than for the older observers. In Experiment 2 (older observers only), the cue duration was doubled, and older observers had a larger magnitude of cuing effect than found in Experiment 1 but not as large as what would be expected under generalized slowing. The results indicated that older observers had difficulty with interpreting the cue and setting search parameters when the target varied across trials.

Adult↗

PubMed2006

Directed forgetting in older adults using the item and list methods.

Four experiments investigated age-group differences in directed forgetting. Experiments 1A and 1B used the item method with recall (1A) and recognition (1B). Both of these experiments showed evidence of directed forgetting for both younger and older adults. The list method was used in Experiments 2A (recall) and 2B (recognition). For these experiments, there was directed forgetting when recall, but not recognition, was the dependent measure. Again, these results were found for younger and older adults. These results are discussed in terms of how different presentation types lead to the use of different theoretical mechanisms of directed forgetting (e.g., differential encoding, retrieval inhibition). Thus, it appears that both older and younger adults engage in adaptive memory strategies.

Adolescent↗

PubMed2006

Directed forgetting of a single item.

In two experiments, we investigated directed forgetting of a single item. We presented participants with two phone numbers to remember and instructed half of the participants to forget the first phone number. The first number was either learned on a single trial (Experiment 1) or on three trials (Experiment 2). In Experiment 1, there was evidence of directed forgetting as a result of differential encoding; the forget instruction affected recall and recognition for both phone numbers. In Experiment 2, the evidence favored differential rehearsal because the forget instruction affected recall but not recognition. These results indicate that instructions to forget can affect memory of single items.

Cues↗

PubMed2005

Recall order determines the magnitude of directed forgetting in the within-participants list method.

In three experiments, we investigated the effect of recall order on directed forgetting when the within-participants list method is used. Experiment 1 showed that participants tend to recall to-be-remembered (R) items before to-be-forgotten (F) items when they can recall items in any order. In Experiment 2, recall order was manipulated (F-R or R-F). The results showed that only the R-F order led to directed forgetting. Finally, in Experiment 3, recall order was also manipulated, and half of the participants were explicitly instructed to use a relational strategy when both F and R items were presented. Again, only the R-F order led to directed forgetting. These results demonstrate that directed forgetting under the list method hinges on the output order in which participants recall the F and R information. Thus, output order should be taken into account by researchers investigating specific mechanisms that lead to directed forgetting.

Humans↗

PubMed2004

Location cuing and response time distributions in visual attention.

The allocation of visual attention was investigated in two experiments. In Experiment 1 (n = 24), a peripheral cue was presented, and in Experiment 2 (n = 24), a central cue was used. In both experiments, cue validity was 90%, and the task was four-choice target identification. Response time distributions were collected for valid trials over five cue-target stimulus onset asynchronies (SOAs), and ex-Gaussian parameters were extracted. In both experiments, only the mean of the Gaussian component decreased as a function of cue-target SOA, which implied a strict time axis translation of the distributions. The results were consistent with sequential sampling models featuring a variable delay in the onset of information uptake.

Attention↗

PubMedDate not supplied

Aging and comparative search for feature differences.

In a comparative visual search experiment, two halves of a display contained visual primitives of various shapes and colors. These halves were identical (50% of trials) or contained a non-matching pair (50% of trials). Response time (RT), accuracy, and eye movements were measured in both young and older adults. There were Age Group x Display Size interactions found for RT, with older adult RT affected more than younger adult RT by increases in display size. This interaction was consistent with predictions generated by sequential-sampling models for RT. There were age group main effects on fixation number and fixation duration, but no age group main effects on accuracy, saccade amplitude, or measures of scan-path efficiency; this indicated that search strategies were similar across age groups. Overall, the results showed no special age group deficits for comparative visual search.

Adolescent↗