Biomedical subjects

Colin M MacLeod

Publications and source records attributed to Colin M MacLeod.

10 recordsLinked to original sources

PubMed2006

Endogenous versus exogenous attentional cuing effects on memory.

Three experiments were conducted to investigate the influence of early attentional cuing effects on subsequent memory. In an incidental study phase, a cue preceded two simultaneously displayed words. An endogenous cue (row of arrows pointing toward one word) or an exogenous cue (row of stars at the location of one word) indicated which word to read aloud. In a subsequent test phase, memory for these cued and uncued words was measured. In Experiment 1, these attentional manipulations had almost no effect on subsequent implicit memory measured using a speeded reading (naming) test. Experiments 2 and 3 demonstrated that, on an explicit memory test, words were reliably better recognized in the endogenous condition than in the exogenous condition. These results suggest that endogenous attentional cues promote more active processing and hence elaboration of words, assisting their subsequent conscious retrieval.

Adult↗

PubMed2006

Negative affect words prime beer consumption in young drinkers.

Negative affect is consistently associated with pathological aspects of alcohol use. Priming of motivation for alcohol by negative affect cues may contribute to this relationship. This study sought to determine whether: (a) exposure to negative affect words primes actual drinking behavior; (b) this effect is related to severity of alcohol problems; and (c) these effects are moderated by gender and anxiety sensitivity. Prime words (negative, positive, neutral) were administered using a synonym generation task. Primed drinking behavior was measured in a taste-test procedure, using placebo beer. Drinking scores were significantly greater in the negative affect condition than in the other two conditions, which did not differ from each other. Problem drinking severity directly predicted priming effects of negative affect words but was unrelated to drinking in the other two word prime conditions. Anxiety sensitivity was unrelated to drinking in any condition. Even unobtrusive exposure to negative affect cues can prime drinking behavior in young drinkers, and this effect is tied to the severity of alcohol problems.

Adult↗

PubMed2006

Re-exposure to studied items at test does not influence false recognition.

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.

Analysis of Variance↗

PubMed2004

False recognition without intentional learning.

Asked to memorize a list of semantically related words, participants often falsely recall or recognize a highly related semantic associate that has not been presented (the critical lure). Does this false memory phenomenon depend on intentional word reading and learning? In Experiment 1, participants performed a color identification task on distractor words from typical false memory lists. In Experiment 2, participants read the same words. In both experiments, the primary task was followed by a surprise recognition test for actually presented and unpresented words, including the critical lures. False alarms to critical lures were robust and quite equivalent across the two experiments. These results are consistent with an activation/monitoring account of false memory, in which processing of semantic associates can evoke false memories even when that processing is incidental.

Color Perception↗

PubMed2003

Hypnotic control of attention in the Stroop task: a historical footnote.

Raz, Shapiro, Fan, and Posner (2002) have recently provided a compelling demonstration of enhanced attentional control under post-hypnotic suggestion. Using the classic color-word interference paradigm, in which the task is to ignore a word and to name the color in which it is printed (e.g., RED in green, say "green"), they gave a post-hypnotic instruction to participants that they would be unable to read. This eliminated Stroop interference in high suggestibility participants but did not alter interference in low suggestibility participants. replicated this pattern and further demonstrated that it is not due to a visual strategy (such as blurring or looking at a different location). As a historical footnote, we describe a "case study" from 18 years ago in which we observed the same result using a hypnotic instruction to a single highly suggestible individual that he could not read. The elimination of Stroop interference has important implications for both the study of attention and the study of hypnosis.

Attention↗

PubMed2003

Effects of negative and positive mood phrases on priming of alcohol words in young drinkers with high and low anxiety sensitivity.

This study investigated whether potential emotional cues for drinking activate alcohol concepts in young drinkers. Participants were 84 university freshmen with high or low levels of anxiety sensitivity (AS). A verbal priming task measured activation (i.e., priming) of alcohol concepts (e.g., beer) by positive and negative mood phrases. Time to read alcohol target words was the dependent measure. Negative mood phrases consistently primed alcohol targets; positive mood phrases did not. Degree of negative mood priming did not differ as a function of gender or AS. Reported tendency to drink in bad moods predicted negative mood priming in women, whereas men showed negative mood priming irrespective of their reported drinking tendency. A general association between negative mood priming and severity of alcohol problems also emerged.

Affect↗

PubMed2002

Covert operations: orthographic recoding as a basis for repetition priming in word identification.

When a word is generated from a semantic cue, coincident orthographic visualization of that word may cause priming on a subsequent perceptual identification test. A task was introduced that required subjects to visualize the orthographic pattern of auditorily presented words. When used at study, this task produced a pattern of priming similar to that produced by a generate study task. When used at test, equal priming on the orthographic task was produced by read and generate study tasks but not by a generate study task that failed to invite orthographic visualization. Priming on perceptually based word identification tests that results from a generate study episode may be largely due to orthographic recoding of the target rather than to conceptual processing.

Analysis of Variance↗

PubMed2002

The crucial roles of stimulus matching and stimulus identity in negative priming.

Negative priming refers to the situation in which an ignored item on an initial prime trial suffers slowed responding when it becomes the target item on a subsequent probe trial. In this experiment (and a replication), we demonstrate two ways in which stimulus consistency (matching) governs negative priming. First, negative priming for identical words occurred only when the prime distractor changed color when it became the probe target (i.e., constant cue to read the red word); negative priming disappeared when the prime distractor retained its color as the probe target (i.e., cue switches from read the red prime word to read the white probe word). Second, negative priming occurred for identical words, but not for semantically related words, whether related categorically or associatively. This pattern of results is consistent with a memory retrieval account, but not with an inhibition account of negative priming, and casts doubt on whether there is semantic negative priming for words.

Affect↗

PubMed2002

Presenting two color words on a single Stroop trial: evidence for joint influence, not capture.

MacLeod and Hodder (1998) demonstrated that presenting two different incongruent color words in the same color on a single Stroop trial resulted in no more interference than did presenting the same incongruent color word twice, and concluded that the first word captured attention, blocking out the second. They also showed that, within a trial, neither stimulus onset asynchrony between the two items nor the presence/absence of a visible gap between the two items had any effect. We replicated all of their empirical findings. Then, by extending their design and factorially combining three types of items--incongruent words, congruent words, and control nonwords--within a trial, we demonstrated that both items within a trial do influence processing, with the contribution of the second greater than that of the first. These results are incompatible with a capture account and suggest instead that the word dimension continues to be monitored during the attempt to identify and produce the name of the color.

Adult↗

PubMedDate not supplied

Anxiety and explicit alcohol-related memory in problem drinkers.

Anxiety is associated with increased craving following in vivo cue exposure in alcoholics. Theoretical accounts [Psychol. Rev. 97 (1990) 147.] have proposed that conscious, deliberate cognitive processes underlie increased craving in drinkers who are trying to abstain. The present study tested the hypothesis that anxiety is associated with biases in explicit (i.e., conscious, deliberate) memory that promote recall of alcohol-related concepts in response to negative affective cues. Fifty-two (seven females) outpatient problem drinkers performed a cued recall task that assessed memory for alcohol-related (ALC), negative affective (NEG), and neutral (NEU) target concepts that had been paired with NEG, ALC, and NEU cues during an incidental study phase. Higher anxiety was associated with increased recall of ALC targets paired with NEG cues. State and trait anxiety were intercorrelated, with higher levels coinciding with a higher frequency of drinking in negative mood states. These findings demonstrate a correspondence between anxiety and alcohol-related memory, and suggest that explicit memory biases may contribute to increased subjective responses (e.g., craving, expectancies) to alcohol stimuli in anxious problem drinkers.

Adult↗