Research Projects in our Lab

The Cognitive Psychophysiology of Emotion

Much of my recent research has concerned how emotionally evocative language is processed, and its effect on attention and memory. For most of this work, we record EEG while undergraduates are presented with words, phrases, or sentences that are emotionally neutral, or emotionally arousing, and must deal with the material in various ways. Typically, averaged event-related potentials as well as behavioral responses serve as the dependent measures in this work.

Sample projects and abstracts:

Limits to the automaticity of responses to emotional words

Ira Fischler, Romko Sikkema, Vincent Van Veen, Michelle Simmons, & Peter Lang. Emotion and attention in the comprehension of single words: An ERP analysis.

Single words varying in emotional pleasantness, or valence, and arousal, were presented visually to undergraduate students, and event-related brain potentials to those words recorded. Over five experiments, the emotionally arousing words, whether pleasant or unpleasant, were associated with a late positive potential relative to the emotionally neutral, less arousing words. The presence, latency and magnitude of this emotionality effect was a function of the particular task to be done with the words: When the task involved consideration of emotionality, the late postivity emerged as early as 300 msec after word onset, and continued for nearly a half second. In contrast, when the task required semantic analysis on a different dimension of meaning, the late positivuty was smaller, did not appear until 450 msec post-onset, and lasted less than 300 msec. When a lexical decision was made to the words, there was only a small and insignificant late positivity for emotional words. Our results suggest that although the cortical response to arousing words resembles that to emotionaly evocative pictures, it is less sustained, and more dependent on how the word is dealt with. There was no evidence for an early, preattentive effect of word emotionality on the ERPs.

Levels of processing, word emotionality, and subsequent memory

Ira Fischler, Candice Mills, Cary Kemp, Michael McKay. Word emotionality, levels of processing and subsequent memory: An ERP analysis.

Memory for the occurrence of emotionally evocative words is often better than for other words. It has been suggested that this emotionality effect on memory is due to a more articulated and distinctive encoding for the emotional words. This is similar to the explanation given for the advantage of “deep” semantic over “shallow” orthographic processing. We therefore concurrently manipulated word emotionality and level of processing in an incidental memory paradigm. During the study phase, participants made either animateness (semantic) or double-letter (orthographic) judgments to emotionally pleasant, unpleasant and neutral words. In a subsequent memory test, studied emotional words were recognized better than were neutral words. Event-related potentials elicited by emotional words at study showed a topographically broad, enhanced late positivity (c. 400-700 ms post-onset), relative to neutral words, but only for the semantic encoding task. The emotionality effect in the ERPs was also attenuated for words that were not subsequently recognized. In contrast, the emotionality effect on memory was at least as great for the orthographic task as for the semantic task. A similar pattern of results was obtained when memory for studied words was manipulated by a distracting secondary task during the animateness decision. These results suggest that the effects of emotionality, on the one hand, and of other factors that influence encoding and memory for words, are at least in part separable.

Effects of emotionality of words in phrases on event-related brain potentials

Ira Fischler, David Goldman, Mireille Besson, Michael McKay, & Margaret Bradley. Effects of Emotionality of Words in Word Phrases on Event-Related Brain Potentials.

Previous work has shown that viewing of individual emotionally evocative words (e.g., pleasure, rape) is associated with an enhanced late positivity in the event-related brain potentials (ERPs) to those words, beginning as early as 350 ms after word onset. In the present study, emotional and neutral words were combined into two-word modifier-noun phrases (e.g., starving puppy) and presented visually with an SOA of 750 ms. When the task focused attention on the word pair as a phrase (Experiment 1), effects of the emotionality of the first word on the ERPs were absent, and those to the second word enhanced, compared to a task that focused attention on the individual words (Experiment 2). There was little effect of the emotional congruence between modifier and noun on the ERPs. These results suggest that in normal discourse processing, the emergent emotional meaning of the phrase can supercede, rather than follow, any automatic emotional responses to individual words.

Emotion, anxiety, and predictive inferences: An ERP investigation

Ira Fischler, Michael McKay, and Peter Lang. Emotion, Anxiety and Predictive Inferences in Reading: An ERP investigation.

Anxious and nonanxious students read short context sentences that invited a predictive inference about potential outcomes (e.g., Your father collapses as he crosses the room..) The contexts were pleasant, unpleasant or neutral in emotional tone. Completion sentences were then shown, one word at a time, that either confirmed (He stops breathing and…) or disconfirmed (He stops smiling and…) the predictive outcome. For both groups, emotional context sentences were read more slowly than neutral sentences. Confirming target words were associated with a reduced N400 component in the ERPs, and this reduction was modulated by emotional tone and anxiety, with anxious students demonstrating smaller, rather than larger, N400 reductions to pleasant as well as unpleasant scenarios. Although both groups rated the confirming outcomes as more plausible than the disconfirming ones, this difference interacted with emotionality and anxiety, with the anxious students rating the confirmed unpleasant scenarios as especially plausible.

Other Recent Research on Attention and Memory

More broadly, we have been interested in a variety of topics concerned with questions ranging from the role of attention in encoding and retrieval, to how metaphors are understood. Much of this work has been in projects that graduate students have developed as part of their masters or dissertation research in our lab.

Sample projects and abstracts:

Cognitive style and recall of text: EEG alpha power as a predictor

Michael McKay, Ira Fischler and Bruce Dunn. Cognitive Style and Recall of Text: An EEG analysis

Cognitive processing style refers to an individual’s characteristic approach to processing information. One popular bipolar dimension is the contrast between “analytic” and “holistic” styles. Such style differences should be reflected in differences in underlying neural processes. Recent studies (e.g., Dunn & Reddix, 1991; Glass & Riding, 1999) suggest that topographic patterns of EEG alpha activity (8-13 Hz) may reflect these differences. EEG was collected at 19 sites during eyes-open baseline, and during reading and recall of short text passages. Forty adults (20 males) were presented passages of material ranging from highly structured expository text to minimally structured poetry. Lower baseline alpha activity was significantly correlated with recall of the expository text across widely distributed sites, but did correlate with recall of poetry. The usefulness and limits of baseline EEG measures of cognitive style are discussed.

Remembering, knowing, and confidence: ERP indicants of recognition memory

Brian Howland and Ira Fischler. Remembering, knowing, and confidence: ERP indicants of recognition memory

In a study-test recognition memory task, students indicated whether they remembered or just knew that a word was old, as well as their confidence in the old/new judgment. A late centro-parietal positive potential in the ERPs recorded during the recognition phase of the task was significantly greater for recognized old words than for missed old words. The timing and topography of this component was similar whether the decision was remember or know, although controlling for confidence, the amplitude of the ERP memory component was greater for remember than know judgments. The behavioral and ERP findings are consistent with single-process, dua-criterion models of the relationship between these subjective judgments of memory.

Contextual interference and retrieval practice in retention of a novel cognitive skill

Nancy Lincoln & Ira Fischler. Contextual interference and retrieval practice in retention of a novel cognitive skill

Three experiments were conducted to investigate two different processing mechanisms of the contextual interference effect, which states that the larger the amount of interference from other items at the time of learning, the greater the subsequent long-term retention and transfer of the information that has been learned (Battig, 1972). Intraitem processing theories focus on the reconstruction of to-be-learned items from memory during acquisition, whereas interitem or relational processing theories focus on contrasts and comparisons between items during learning. Participants learned sets of unique or related Kanji characters mapped onto sequential mathematical rules in various practice schedules (random, blocked, blocked with an intervening task, and semi-random) and were then given a retention test 48 hours later. A strong contextual interference effect was found in all three experiments, extending the current literature to the higher-level learning of cognitive skills. Marginal effects of relational processing were found; but more interestingly, the claim that a blocked-plus-intervening-task schedule could replicate the demands and workload of a random schedule (Carlson and Yaure, 1990) was not supported. Furthermore, qualitative differences amongst groups that learned the rules one at a time, or in groups of two, three, or six, are discussed in terms of varying levels of proactive interference. Results are discussed in an intraitem processing framework, and theoretical explanations are adopted from the literature on the distribution of practice (e.g. deficient processing theories) to understand underlying processes of random and blocked practice schedules. However, more research is clearly needed on the relational aspects of contextual interference, and of skill learning in general.

Functions of the central executive component of working memory

Michelle Simmons and Ira Fischler. Functions of the central executive component of working memory: A dual-task version of the n-back task.

Working memory is thought of as a cognitive process capable of briefly storing and manipulating information. Working memory consists of two domain-specific slave systems and a central executive, which is responsible for coordinating this simultaneous storage and manipulation of information and other executive functions. The n-back task is an experimental task that recently has been used to examine the neurophysiological substrates of working memory. In the n-back task, participants are presented with a series of stimuli and are to indicate whether the current stimulus matches the stimulus presented n stimuli back in the series, where n equals a number between 0 and 3. The results of these neuroimaging studies suggest that the n-back requires executive control at higher levels of n, but not at lower levels of n. This hypothesis was tested in 3 experiments in which participants were asked to perform versions of the n-back task concurrent with secondary tasks designed to tax the various component processes of working memory. In Experiment 1, an auditory-verbal n-back was paired with a visual-spatial version of the n -back. Relative to the single-task conditions, the dual-task conditions produced marked interference in the 2- and 3-back tasks, but not in the 0- and 1-back tasks. In Experiment 2, the verbal and spatial n-backs were again paired but the length of time between stimuli was shortened in order to test a time-sharing hypothesis regarding the results of Experiment 1. The accuracy results replicated the results of experiment 1, but the reaction time data showed interference in the 1-, 2-, and 3-back tasks. In Experiment 3, the auditory-verbal n-back was paired with three visual tasks: a rhyme task, a random keypress task, and a mental rotation task. The results from these dual-task pairings indicate that the results from Experiments 1 and 2 may reflect mere difficulty rather than the need for central executive resources specifically. Taken together the results of these experiments lead to the conclusion that the n-back task is a complex task that relies on multiple processes, some of which can be considered executive processes and others that are less executive in nature.

Attention, distraction and assocation in retrieval of word pairs

Ira Fischler, Mireille Besson and Brian Howland. Attention, distraction and association in episodic memory.

Compared full and divided attention conditions during a recoghntiion memory task. Participants had studied a list of semantically related and unrelated word pairs. During half of the recognition blocks, they concurrently monitored a list of spoken digits for three consecutive odd digits (divided attention condition). Dividing attention at test impaired speed and accuracy of recognition, suggesting that retrieval from long-term episodic memory was attention-demanding; for semantically related pairs, there was less impairment of performance, however.

Learning about the anesthesia machine with transparent and opaque simulations

Ira Fischler, Cynthia Kaschub, David Lizdas & Samsun Lampotang. Understanding of Anesthesia Machine Function is Enhanced with a Transparent Reality Simulation.

Iconic simulations that closely reproduce the visual appearance of the simulated system may provide more efficient transfer of skills to the real system, but by being opaque, fail to encourage deeper learning of the structure and function of the system. Schematic simulations that are more abstract with less visual fidelity but which make system structure and function transparent may enhance that deeper learning, and optimize retention and transfer of learning. Undergraduate students were given a single, one-hour guided learning session with either a Transparent or Opaque version of the Virtual Anesthesia Machine (VAM) simulation. The VAM simulates actual machine function and dynamics and responds in real time to user interventions such as changes in gas flow or concentration. The following day, the learners’ knowledge of machine components, function and dynamics was tested. There were no group differences in self-reported knowledge of anesthesia or the anesthesia machine prior to learning. At test, the groups were comparable in the ability to name the components of the machine, but the Transparent-VAM group provided better and more complete explanations of component function (p = .004), and was more accurate in remembering and inferring cause-and-effect dynamics of the machine and relations among components (p = .013). Schematic simulations that transparently allow the learner to visualize, and explore, underlying system dynamics and relations among components may provide a more effective mental model of the system. This leads to a deeper understanding of how the machine works, and therefore, we believe, how to detect and respond to potentially adverse situations.