Biomedical subjects

D I Lozano

Publications and source records attributed to D I Lozano.

3 recordsLinked to original sources

PubMed2000

Immediate and delayed stimulus repetitions evoke different ERPs in a serial-probe recognition task.

In this study we examined whether event-related potentials (ERPs) associated with stimulus repetition and recognition in a serial-probe recognition task were comparable to ERPs in other tasks that are more typically used to investigate old/new ERP effects. The experiment consisted of 320 trials in which a recognition probe followed a four-item memory set; 160 trials consisted of images depicting common objects that were easy to label (EL task), and 160 trials consisted of images depicting abstract patterns that were difficult to label (DL task). Nineteen participants indicated whether a probe that followed each memory set was or was not presented in the memory set. Half of the probes matched, and half did not match, an item in the preceding memory set. ERPs appeared to reflect two processes--one that differentiated between recently presented stimuli and other stimuli and another that distinguished between repeated stimuli and new stimuli. ERPs to recent probes were more positive than ERPs to other probes in the EL and DL tasks. ERPs to match (old) probes were more positive than ERPs to nonmatch (new) probes only in the EL task.

Adult↗

PubMed1999

Changes in food attitudes as a function of hunger.

This experiment investigated whether hunger selectively influences attitudes toward common food items. Participants completed a take-home questionnaire on which they rated their attitudes toward food and non-food items when they were either hungry (45 participants) or not hungry (45 participants); after returning the questionnaire, participants completed a second take-home questionnaire in the opposite hunger condition. Results of both between-subject and within-subject analyses revealed that participants rated foods more positively when hungry compared to not hungry and that there was no difference in the ratings of non-foods when hungry vs. not hungry. Moreover, attitudes toward high-fat foods changed more as a function of hunger than attitudes toward low-calorie foods. As attitudes are important for guiding behavior, these results suggest that food attitudes influence daily eating patterns and consumer decisions regarding food purchases. The findings may also have important health implications because hunger exerts a greater influence on attitudes toward high-fat foods.

Adult↗

PubMed1998

Event-related potentials and serial position effects in a visual probe recognition task.

In two experiments, we explored the utility of using event-related brain potentials (ERPs) evoked during picture recognition to examine the cognitive and neural processes underlying primacy and recency effects. Each experiment consisted of 210 trials in which a recognition probe followed a 12-picture sequence (105 match and 105 nonmatch trials). The 105 match-probe trials consisted of 35 trials in which the probe matched a prime memory set item (Positions 1-3), 35 in which the probe matched a middle memory set item (Positions 6-8), and 35 in which the probe matched a recent memory set item (Positions 10-12). Behavioral results revealed recency but not primacy effects in both experiments. Recent probes, compared with prime and middle probes, evoked ERPs that were more positive from approximately 300 to 400 ms; this enhanced positivity occurred in a positive component peaking around 315 ms and a negative component peaking around 365 ms. These findings fit more closely with the notion of short-term memory as an activation of elements in long-term memory than as a distinct memory store (or stores) separate from long-term memory.

Adult↗