Effects of handedness and saccadic bilateral eye movements on components of autobiographical recollection

The effects of handedness and saccadic bilateral eye movements on autobiographical recollection were investigated. Recall of autobiographical memories was cued by the use of neutral and emotional words. Autobiographical recollection was assessed by the autobiographical memory questionnaire. Experiment 1 found that mixed-handed (vs. right handed) individuals demonstrated greater levels of autobiographical recollection on the components of seeing, hearing, and emotion. Experiment 2 found that following 30 s of bilateral eye movements, greater levels of autobiographical recollection were demonstrated on the components of reliving, seeing, hearing, emotion, self-perspective and veridicality. The results extend previous research by showing that the recollective components of real world memories can be enhanced by either mixed-handedness or eye movements. In addition, these results provide a bridge between laboratory studies of recollection and autobiographical recollection. The findings are considered in terms of research on the cognitive neuroscience of autobiographical memory.     

Influence of handedness and bilateral eye movements on creativity

We investigated the effects of increased inter-hemispheric interaction (IHI) on five creativity dimensions (appropriateness, detail, categorical distinctiveness, fluency, and originality) of the Alternate Uses Task. Two methods were used to indicate degree of IHI. Trait IHI was indicated by individual differences in handedness, mixed-handers showing greater IHI than strong-handers. State IHI was directly manipulated by central (control group) and bilateral viewing conditions of a 30 s eye movement task (EM). Results indicate significantly higher creativity for mixed-handers, as compared to strong-handers, for all five sub-scores separately and linearly combined. Bilateral EM increased originality and categorical distinctiveness (i.e., flexibility) of strong-handers, but had no effect on mixed-handers. Strong-handers in the bilateral EM group were not different from mixed-handers. Additionally, the bilateral EM effect on strong-handers had different durations for originality (up to 7–9 min) and categorical distinctiveness (up to 3 min). The results suggest that greater IHI can facilitate creativity of strong-handers, but that the characteristically higher IHI of mixed-handers was unaffected by the bilateral EM manipulation.     

The impact of eye movements on a verbal creativity task

Bilateral eye movements (EMs) have been shown to induce cognitive enhancements for episodic memory, attention, and divergent thinking. Increased interhemispheric interaction has been suggested as a possible mechanism behind the EM effect, but other theories, including an increase in attentional control following EMs have also been proposed. The present research explored whether the bilateral EM effect could be extended to a creativity task that draws heavily on convergent thinking. Participants were randomly assigned to one of four EM conditions (bilateral, centre control, right-centre, or left-centre) and were presented with compound remote associate problems. After 7 s, participants were asked to make a solution/non-solution judgement to a target word presented in the left or right visual field. Bilateral and right-centre EM conditions exhibited enhanced performance on the task, with the bilateral condition demonstrating the best performance for solution targets and the right-centre condition presenting the best performance for non-solution targets. The implications of these findings are discussed in light of the neural components of creativity and theories surrounding the effects of EMs on cognition.     

Unity and diversity of executive functions in creativity

Increasing evidence suggests that executive functions (EFs) – a set of general-purpose control processes that regulate thoughts and behaviors – are relevant for creativity. However, EF is not a unitary process, and it remains unclear which specific EFs are involved. The present study examined the association between the three EFs, both uniquely (EF-Specific) and together (Common EF), and three measures of creativity. Participants (N = 47) completed a divergent thinking test, and self-reported their real-life creative accomplishments. A subset of participants indicated their involvement in the artistic or information technology (IT) professions. Results indicated that fluency (but not originality) of divergent thinking was uniquely predicted by working memory Updating. Better response Inhibition predicted higher number of real-world artistic creative achievements. Involvement in the artistic (versus IT) professions was associated with better Common EF, and with enhanced mental set Shifting abilities. Results demonstrate that different EFs predict creativity depending on its operational definition.     

Social cues for creativity: The impact of behavioral mimicry on convergent and divergent thinking

We present behavioral mimicry as a social cue for creative thinking. Specifically, we argue that being mimicked by an interaction partner cues convergent thinking by signalling a social opportunity for collaboration, while not being mimicked cues divergent thinking by signalling a social demand for improvisation and innovation. To test this theory, we experimentally manipulated whether individuals were subtly mimicked or not by an experimenter during a 5 min social interaction, and subsequently measured participants’ capacity for convergent thinking (Experiment 1) and divergent thinking (Experiment 2). The results point to the importance of understanding how social relationships influence the creative processes and contributes to the growing understanding of the social function of behavioral mimicry.     

The valence-specific laterality effect in free viewing conditions: The influence of sex, handedness, and response bias

The right hemisphere has often been viewed as having a dominant role in the processing of emotional information. Other evidence indicates that both hemispheres process emotional information but their involvement is valence specific, with the right hemisphere dealing with negative emotions and the left hemisphere preferentially processing positive emotions. This has been found under both restricted (Reuter-Lorenz & Davidson, 1981) and free viewing conditions (Jansari, Tranel, & Adophs, 2000). It remains unclear whether the valence-specific laterality effect is also sex specific or is influenced by the handedness of participants. To explore this issue we repeated Jansari et al.'s free-viewing laterality task with 78 participants. We found a valence-specific laterality effect in women but not men, with women discriminating negative emotional expressions more accurately when the face was presented on the left-hand side and discriminating positive emotions more accurately when those faces were presented on the right-hand side. These results indicate that under free viewing conditions women are more lateralised for the processing of facial emotion than are men. Handedness did not affect the lateralised processing of facial emotion. Finally, participants demonstrated a response bias on control trials, where facial emotion did not differ between the faces. Participants selected the left-hand side more frequently when they believed the expression was negative and the right-hand side more frequently when they believed the expression was positive. This response bias can cause a spurious valence-specific laterality effect which might have contributed to the conflicting findings within the literature.     

Enhanced divergent thinking and creativity in musicians: a behavioral and near-infrared spectroscopy study

Empirical studies of creativity have focused on the importance of divergent thinking, which supports generating novel solutions to loosely defined problems. The present study examined creativity and frontal cortical activity in an externally-validated group of creative individuals (trained musicians) and demographically matched control participants, using behavioral tasks and near-infrared spectroscopy (NIRS). Experiment 1 examined convergent and divergent thinking with respect to intelligence and personality. Experiment 2 investigated frontal oxygenated and deoxygenated hemoglobin concentration changes during divergent thinking with NIRS. Results of Experiment 1 indicated enhanced creativity in musicians who also showed increased verbal ability and schizotypal personality but their enhanced divergent thinking remained robust after co-varying out these two factors. In Experiment 2, NIRS showed greater bilateral frontal activity in musicians during divergent thinking compared with nonmusicians. Overall, these results suggest that creative individuals are characterized by enhanced divergent thinking, which is supported by increased frontal cortical activity.     

Reduced misinformation effects following saccadic bilateral eye movements

The effects of saccadic bilateral (horizontal) eye movements on memory for a visual event narrative were investigated. In the study phase, participants were exposed to a set of pictures accompanied by a verbal commentary describing the events depicted in the pictures. Next, the participants were asked either misleading or control questions about the depicted event and were then asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Finally, recognition memory was tested using the remember-know procedure. It was found that bilateral eye movements increased true memory for the event, increased recollection, and decreased the magnitude of the misinformation effect. The findings are discussed in terms of source monitoring, dual-process theories of memory and the potential neural foundations of such effects.     

Bilateral saccadic eye movements and tactile stimulation,but not auditory stimulation,enhance memory retrieval

Recent research has shown superior memory retrieval when participants make a series of horizontal saccadic eye movements between the memory encoding phase and the retrieval phase compared to participants who do not move their eyes or move their eyes vertically. It has been hypothesized that the rapidly alternating activation of the two hemispheres that is associated with the series of left–right eye movements is critical in causing the enhanced retrieval. This hypothesis predicts a beneficial effect on retrieval of alternating left–right stimulation not only of the visuomotor system, but also of the somatosensory system, both of which have a strict contralateral organization. In contrast, this hypothesis does not predict an effect, or a weaker effect, on retrieval of alternating left–right stimulation of the auditory system, which has a much less lateralized organization. Consistent with these predictions, we replicated the horizontal saccade-induced retrieval enhancement (Experiment 1) and showed that a similar retrieval enhancement occurs after alternating left–right tactile stimulation (Experiment 2). Furthermore, retrieval was not enhanced after alternating left–right auditory stimulation compared to simultaneous bilateral auditory stimulation (Experiment 3). We discuss the possibility that alternating bilateral activation of the left and right hemispheres exerts its effects on memory by increasing the functional connectivity between the two hemispheres. We also discuss the findings in the context of clinical practice, in which bilateral eye movements (EMDR) and auditory stimulation are used in the treatment of post-traumatic stress disorder.     

Effects of bilateral eye movements on gist based false recognition in the DRM paradigm

The effects of saccadic bilateral (horizontal) eye movements on gist based false recognition was investigated. Following exposure to lists of words related to a critical but non-studied word participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Subsequent testing of recognition memory revealed that those who undertook bilateral eye movement were more likely to correctly recognise previously presented words and less likely to falsely recognise critical non-studied associates. This result joins other research in demonstrating the conditions in which false memory effects can be attenuated.     

Effects of saccadic bilateral eye movements on memory in children and adults: an exploratory study

The effects of saccadic bilateral (horizontal) eye movements on true and false memory in adults and children were investigated. Both adults and children encoded lists of associated words in the Deese-Roediger-McDermott paradigm followed by a test of recognition memory. Just prior to retrieval, participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. For studied information, the results for adults replicated previous work; bilateral eye movements were demonstrated to increase the accuracy of memory by increasing the hit rate and reducing the false alarm rate for related and unrelated recognition test lures. The results for children also indicated an improvement in memory accuracy, and like adults, was due to both an increase in the hit rate and a reduction in the false alarm rate. In spite of these similarities, the effects of bilateral eye movements differed between adults and children for critical unstudied words; i.e., those associated with the theme of the list. Only in adults did, bilateral eye movements reduce associative false memories; children did not show a reduction in false memory for critical associates. This produced a dissociation between the effects of eye movements on associative false memory as a function of age. The results are discussed from a developmental perspective in terms of potential mechanisms underlying true and false memory.     

Effects of thematic and lexical priming on readers' eye movements

The study was inspired by Ehrlich & Rayner (1981). In the study semantic context effects were investigated during on-line discourse processing. Readers' eye movements were registered to see whether words that were semantically closely related to the global theme of the text were read faster than words that did not have any apparent semantic link to the discourse theme. In addition, lexical priming was examined by presenting an identity prime earlier in the text. The results showed that non-thematic words were regressed to more often than thematic words. Regressions were typically initiated after reaching a clause or sentence boundary. Regressions were thus assumed to be made in order to integrate non-thematic words into the previous context. Modest negative correlations were found between word's fixation time and its relative predictability. No effects of lexical priming were observed. It was concluded that moderately constraining discourse contexts produce negligible effects on word recognition.     

Verbal fluency and creativity: General and specific contributions of broad retrieval ability (Gr) factors to divergent thinking

The Cattell–Horn–Carroll (CHC) model of intelligence views creativity as a first-level factor within the second-level factor of broad retrieval ability (Gr), alongside other first-level abilities such as ideational fluency and word fluency. Traditional methods of measuring creativity, however, confound idea quality with idea quantity, which might exaggerate the relationship between creativity scores and verbal fluency factors. Participants (n = 131 adults) completed two divergent thinking tasks (unusual uses for a rope and a box), which were scored using newer methods that effectively separate creativity (scored via subjective ratings) and fluency (scored as number of responses). They then completed 16 verbal fluency tasks that assessed six lower-order Gr factors: word fluency, associational fluency, associative flexibility, ideational fluency, letter fluency, and dissociative ability. Viewed singly, many of the lower-order factors significantly predicted creative quality and fluency. General Gr had substantial effects on creative quality (standardized β = .443) and fluency (β = .339) in a higher-order model as well as in a bifactor model (quality β = .380, fluency β = .327). Moreover, general Gr was the only significant predictor in the bifactor model, suggesting that it, not the specific factors, was most important. All effects were essentially the same after controlling for typing speed and vocabulary knowledge. The findings thus support the CHC view of creativity/originality as a lower-order component of Gr, illuminate the relationships between creativity and first-level Gr factors, extend the study of creativity and intelligence beyond fluid intelligence, and further indicate that creativity is more closely tied to cognitive abilities than creativity research has yet recognized.     

Hemispheric connectivity and the visual–spatial divergent-thinking component of creativity

Background/hypothesis

Divergent thinking is an important measurable component of creativity. This study tested the postulate that divergent thinking depends on large distributed inter- and intra-hemispheric networks. Although preliminary evidence supports increased brain connectivity during divergent thinking, the neural correlates of this characteristic have not been entirely specified. It was predicted that visuospatial divergent thinking would correlate with right hemisphere white matter volume (WMV) and with the size of the corpus callosum (CC).

Methods

Volumetric magnetic resonance imaging (MRI) analyses and the Torrance Tests of Creative Thinking (TTCT) were completed among 21 normal right-handed adult males.

Results

TTCT scores correlated negatively with the size of the CC and were not correlated with right or, incidentally, left WMV.

Conclusions

Although these results were not predicted, perhaps, as suggested by Bogen and Bogen (1988), decreased callosal connectivity enhances hemispheric specialization, which benefits the incubation of ideas that are critical for the divergent-thinking component of creativity, and it is the momentary inhibition of this hemispheric independence that accounts for the illumination that is part of the innovative stage of creativity. Alternatively, decreased CC size may reflect more selective developmental pruning, thereby facilitating efficient functional connectivity.     

The effects of interword spacing on the eye movements of young and older readers

Recent evidence indicates that older adults (aged 65+) are more disrupted by removing interword spaces than young adults (aged 18–30). However, it is not known whether older readers also show greater sensitivity to the more subtle changes to this spacing that frequently occur during normal reading. In the present study the eye movements of young and older adults were examined when reading texts for which interword spacing was normal, condensed to half its normal size or expanded to 1.5 times its normal size. Although these changes in interword spacing affected eye movement behaviour, this influence did not differ between young and older adults. Furthermore, a word frequency manipulation showed that these changes did not affect word identification for either group. The results indicate that older adults can adapt their eye moment behaviour to accommodate subtle changes in the spatial layout of text equally effectively as young adults.     

An integrated model of eye movements and visual encoding

Recent computational models of cognition have made good progress in accounting for the visual processes needed to encode external stimuli. However, these models typically incorporate simplified models of visual processing that assume a constant encoding time for all visual objects and do not distinguish between eye movements and shifts of attention. This paper presents a domain-independent computational model, EMMA, that provides a more rigorous account of eye movements and visual encoding and their interaction with a cognitive processor. The visual-encoding component of the model describes the effects of frequency and foveal eccentricity when encoding visual objects as internal representations. The eye-movement component describes the temporal and spatial characteristics of eye movements as they arise from shifts of visual attention. When integrated with a cognitive model, EMMA generates quantitative predictions concerning when and where the eyes move, thus serving to relate higher-level cognitive processes and attention shifts with lower-level eye-movement behavior. The paper evaluates EMMA in three illustrative domains — equation solving, reading, and visual search — and demonstrates how the model accounts for aspects of behavior that simpler models of cognitive and visual processing fail to explain.     

Effects of changes in narrative time on eye movements and recognition responses

Abstract

Gibbs and O'Brien (1990) recently claimed that the images that people associate with everyday idioms reflect the deep conceptual metaphors that underlie the meanings of those idioms. However, because idiomatic strings can convey both a literal and an idiomatic meaning, people must be able to inhibit or ignore literal meanings if they are to produce mental images that uniquely reflect idiomatic meanings. We investigated the potential interference between literal and idiomatic meanings in three experiments. Experiment 1 used a mental-image production task similar to that used by Gibbs and O'Brien. Counter to Gibbs and O'Brien's claim, the images that we obtained referred overwhelmingly to the literal meanings of idiomatic strings rather than to their idiomatic meanings. Experiments 2 and 3 employed a paraphrase verification task to examine the effects of mental imagery on idiom comprehension. If the images associated with an idiom reflect that idiom's meaning, then imagery should facilitate comprehension. No evidence for facilitation was found in either experiment. Instead, imagery interfered with comprehension, as assessed by paraphrase verification time, both for idiomatic meanings and for literal, concrete meanings. We conclude that the images associated with idioms do not reflect idiom meanings.     

Some effects of alcohol and eye movements on cross-race face learning

This study examines the impact of acute alcohol intoxication on visual scanning in cross-race face learning. The eye movements of a group of white British participants were recorded as they encoded a series of own-and different-race faces, under alcohol and placebo conditions. Intoxication reduced the rate and extent of visual scanning during face encoding, reorienting the focus of foveal attention away from the eyes and towards the nose. Differences in encoding eye movements also varied between own-and different-race face conditions as a function of alcohol. Fixations to both face types were less frequent and more lingering following intoxication, but in the placebo condition this was only the case for different-race faces. While reducing visual scanning, however, alcohol had no adverse effect on memory, only encoding restrictions associated with sober different-race face processing led to poorer recognition. These results support perceptual expertise accounts of own-race face processing, but suggest the adverse effects of alcohol on face learning published previously are not caused by foveal encoding restrictions. The implications of these findings for alcohol myopia theory are discussed.     

Percolating ideas: The effects of caffeine on creative thinking and problem solving

Caffeine is the most widely consumed psychotropic drug in the world, with numerous studies documenting the effects of caffeine on people’s alertness, vigilance, mood, concentration, and attentional focus. The effects of caffeine on creative thinking, however, remain unknown. In a randomized placebo-controlled between-subject double-blind design the present study investigated the effect of moderate caffeine consumption on creative problem solving (i.e., convergent thinking) and creative idea generation (i.e., divergent thinking). We found that participants who consumed 200 mg of caffeine (approximately one 12 oz cup of coffee, n = 44), compared to those in the placebo condition (n = 44), showed significantly enhanced problem-solving abilities. Caffeine had no significant effects on creative generation or on working memory. The effects remained after controlling for participants’ caffeine expectancies, whether they believed they consumed caffeine or a placebo, and changes in mood. Possible mechanisms and future directions are discussed.