Investigating links between creativity anxiety, creative performance, and state-level anxiety and effort during creative thinking.

Identifying ways to enable people to reach their creative potential is a core goal of creativity research with implications for education and professional attainment. Recently, we identified a potential barrier to creative achievement: creativity anxiety (i.e., anxiety specific to creative thinking). Initial work found that creativity anxiety is associated with fewer real-world creative achievements. However, the more proximal impacts of creativity anxiety remain unexplored. In particular, understanding how to overcome creativity anxiety requires understanding how creativity anxiety may or may not impact creative cognitive performance, and how it may relate to state-level anxiety and effort while completing creative tasks. The present study sought to address this gap by measuring creativity anxiety alongside several measures of creative performance, while concurrently surveying state-level anxiety and effort. Results indicated that creativity anxiety was, indeed, predictive of poor creative performance, but only on some of the tasks included. We also found that creativity anxiety predicted both state anxiety and effort during creative performance. Interestingly, state anxiety and effort did not explain the associations between creativity anxiety and creative performance. Together, this work suggests that creativity anxiety can often be overcome in the performance of creative tasks, but likewise points to increased state anxiety and effort as factors that may make creative performance and achievement fragile in more demanding real-world contexts.

Ensembles of human MTL neurons "jump back in time" in response to a repeated stimulus.

Episodic memory, which depends critically on the integrity of the medial temporal lobe (MTL), has been described as "mental time travel" in which the rememberer "jumps back in time." The neural mechanism underlying this ability remains elusive. Mathematical and computational models of performance in episodic memory tasks provide a specific hypothesis regarding the computation that supports such a jump back in time. The models suggest that a representation of temporal context, a representation that changes gradually over macroscopic periods of time, is the cue for episodic recall. According to these models, a jump back in time corresponds to a stimulus recovering a prior state of temporal context. In vivo single-neuron recordings were taken from the human MTL while epilepsy patients distinguished novel from repeated images in a continuous recognition memory task. The firing pattern of the ensemble of MTL neurons showed robust temporal autocorrelation over macroscopic periods of time during performance of the memory task. The gradually-changing part of the ensemble state was causally affected by the visual stimulus being presented. Critically, repetition of a stimulus caused the ensemble to elicit a pattern of activity that resembled the pattern of activity present before the initial presentation of the stimulus. These findings confirm a direct prediction of this class of temporal context models and may be a signature of the mechanism that underlies the experience of episodic memory as mental time travel.

Human medial temporal lobe neurons respond preferentially to personally relevant images.

People with whom one is personally acquainted tend to elicit richer and more vivid memories than people with whom one does not have a personal connection. Recent findings from neurons in the human medial temporal lobe (MTL) have shown that individual cells respond selectively and invariantly to representations of famous people [Quian Quiroga R, Reddy L, Kreiman G, Koch C, Fried I (2005) Nature 435(7045):1102-1107]. Observing these cells, we wondered whether photographs of personally relevant individuals, such as family members, might be more likely to generate such responses. To address this issue, we recorded the activity of 2,330 neurons in the human MTL while patients viewed photographs of varying personal relevance: previously unknown faces and landscapes, familiar but not necessarily personally relevant faces and landscapes, and finally, photographs of the patients themselves, their families, and the experimenters. Our findings indicate that personally relevant photographs are indeed more likely to elicit selective responses in MTL neurons than photographs of individuals with whom the patients have had no personal contact. These findings further suggest that relevant stimuli are encoded by a larger proportion of neurons than less relevant stimuli, given that familiar or personally relevant items are linked to a larger variety of experiences and memories of these experiences.

Anti-saccade performance predicts executive function and brain structure in normal elders.

OBJECTIVE: To assess the neuropsychological and anatomical correlates of anti-saccade (AS) task performance in normal elders. BACKGROUND: The AS task correlates with neuropsychological measures of executive function and frontal lobe volume in neurological diseases, but has not been studied in a well-characterized normal elderly population. Because executive dysfunction can indicate an increased risk for cognitive decline in cognitively normal elders, we hypothesized that AS performance might be a sensitive test of age-related processes that impair cognition. METHOD: The percentage of correct AS responses was evaluated in 48 normal elderly subjects and associated with neuropsychological test performance using linear regression analysis and gray matter volume measured on magnetic resonance imaging scans using voxel-based morphometry. RESULTS: The percentage of correct AS responses was associated with measures of executive function, including modified trails, design fluency, Stroop inhibition, abstraction, and backward digit span, and correlated with gray matter volume in 2 brain regions involved in inhibitory control: the left inferior frontal junction and the right supplementary eye field. The association of AS correct responses with neuropsychological measures of executive function was strongest in individuals with fewer years of education. CONCLUSIONS: The AS task is sensitive to executive dysfunction and frontal lobe structural alterations in normal elders.

Neural activity in the hippocampus and perirhinal cortex during encoding is associated with the durability of episodic memory.

Studies examining medial temporal lobe (MTL) involvement in memory formation typically assess memory performance after a single, short delay. Thus, the relationship between MTL encoding activity and memory durability over time remains poorly characterized. To explore this relationship, we scanned participants using high-resolution functional imaging of the MTL as they encoded object pairs; using the remember/know paradigm, we then assessed memory performance for studied items both 10 min and 1 week later. Encoding trials were classified as either subsequently recollected across both delays, transiently recollected (i.e., recollected at 10 min but not after 1 week), consistently familiar, or consistently forgotten. Activity in perirhinal cortex (PRC) and a hippocampal subfield comprising the dentate gyrus and CA fields 2 and 3 reflected successful encoding only when items were recollected consistently across both delays. Furthermore, in PRC, encoding activity for items that later were consistently recollected was significantly greater than that for transiently recollected and consistently familiar items. Parahippocampal cortex, in contrast, showed a subsequent memory effect during encoding of items that were recollected after 10 min, regardless of whether they also were recollected after 1 week. These data suggest that MTL subfields contribute uniquely to the formation of memories that endure over time, and highlight a role for PRC in supporting subsequent durable episodic recollection.

Musical expertise generalizes to superior temporal scaling in a Morse code tapping task.

A key feature of the brain's ability to tell time and generate complex temporal patterns is its capacity to produce similar temporal patterns at different speeds. For example, humans can tie a shoe, type, or play an instrument at different speeds or tempi-a phenomenon referred to as temporal scaling. While it is well established that training improves timing precision and accuracy, it is not known whether expertise improves temporal scaling, and if so, whether it generalizes across skill domains. We quantified temporal scaling and timing precision in musicians and non-musicians as they learned to tap a Morse code sequence. We found that non-musicians improved significantly over the course of days of training at the standard speed. In contrast, musicians exhibited a high level of temporal precision on the first day, which did not improve significantly with training. Although there was no significant difference in performance at the end of training at the standard speed, musicians were significantly better at temporal scaling-i.e., at reproducing the learned Morse code pattern at faster and slower speeds. Interestingly, both musicians and non-musicians exhibited a Weber-speed effect, where temporal precision at the same absolute time was higher when producing patterns at the faster speed. These results are the first to establish that the ability to generate the same motor patterns at different speeds improves with extensive training and generalizes to non-musical domains.

The neural correlates of recollection: hippocampal activation declines as episodic memory fades.

Memories for certain events tend to linger in rich, vivid detail, and retrieval of these memories includes a sense of re-experiencing the details of the event. Most events, however, are not retained in any detailed way for more than a few days. According to one theory, the hippocampus plays a specific role in supporting episodic retrieval, that is, the re-experiencing of an event as part of one's personal past. This theory predicts that as episodic memories fade over time and are reduced to feelings of familiarity, activity in the hippocampus should no longer be associated with retrieval. We used high-resolution functional imaging to explore neural activity in medial temporal lobe subregions while participants performed a recognition task at both a short (10-min) and long (1-week) study-test delay. For each recognized item, subjects made "Remember/Know" judgments, allowing us to distinguish between items that were consistently episodic across the two tests and items that were initially episodic, but later became merely familiar. Our results demonstrate that activity in the subiculum is specifically associated with episodic recollection. Overall, recollected items were associated with higher activity in the subiculum than other items. For transiently recollected items, there was a decrease in subicular activity across the 1-week delay as memory faded from recollection to familiarity, whereas consistently recollected items were associated with enhanced subicular activity at both delays. These results provide evidence of a link between subicular activation and recollective experience.

Difficulties in detecting behavioral symptoms of frontotemporal lobar degeneration across cultures.

Cross-cultural studies of neurodegenerative disorders are especially important when the disease in question is difficult to diagnose, particularly if symptoms of the illness include behavioral disturbances that may be interpreted differently in different cultures. One such disease is frontotemporal lobar degeneration (FTLD), an early-age-of-onset dementia that disproportionately affects social behavior. We report the demographic and neuropsychologic characteristics of more than 300 patients diagnosed with FTLD in the United States, Greece, and Turkey. We find that patients with the frontal variant of frontotemporal dementia (FTD) are diagnosed at an earlier age and report earlier symptom onset in the United States than in Greece or Turkey. Furthermore, neuropsychologic measures indicate that at diagnosis, FTD patients in the United States are less impaired than patients in Greece and Turkey. Patients with FTD in Greece and Turkey are diagnosed later in the disease, presumably because their behavioral symptoms are not easily detected by the medical system in these countries. Our study underscores the need to create culturally appropriate indices of the behavioral symptoms of FTLD, so that patients may be diagnosed and treated at an earlier stage.

Distraction during relational reasoning: the role of prefrontal cortex in interference control.

We compared the reasoning performance of patients with frontal-variant frontotemporal lobar degeneration (FTLD) with that of patients with temporal-variant FTLD and healthy controls. In a picture analogy task with a multiple-choice answer format, frontal-variant FTLD patients performed less accurately than temporal-variant FTLD patients, who in turn performed worse than healthy controls, when semantic and perceptual distractors were present among the answer choices. When the distractor answer choices were eliminated, frontal-variant patients showed relatively greater improvement in performance. Similar patient groups were tested with a relational-pattern reasoning task that included manipulations of one or two relations and both perceptual and semantic extraneous information. Frontal-variant patients showed performance deficits on all tasks relative to the other subject groups, especially when distracted. These results demonstrate that intact prefrontal cortex (PFC) is necessary for controlling interference from perceptual and semantic distractors in order to reason from relational structure.

Symptoms of frontotemporal dementia provide insights into orbitofrontal cortex function and social behavior.

Recent investigations into the brain substrates of behavioral changes in frontotemporal dementia (FTD) demonstrate that the orbitofrontal cortex (OFC) plays a crucial role in normal social and emotional behavior. The initial symptoms of FTD reflect the early involvement of OFC as well as the disruption of an associated network involving the insula, striatum, and medial frontal lobes. As predicted by patients with other types of OFC lesions, FTD patients show impairments involving stimulus-reward reversal learning, response inhibition, and ability to judge the appropriateness of their behavior in the social context. While the natural reward system remains intact in these patients, that is, patients will seek out directly rewarding stimuli, such as food and sex, with progressive OFC dysfunction they lose the ability to process complex stimulus-reward contingencies. These abnormalities are apparent in their social interactions, which break down early in the disease. Also, deficits in emotion recognition and empathy have been directly linked to OFC atrophy in these patients. In contrast, some patients with early FTD show intact cognitive skills, including memory and executive functioning. Here, we review the behavioral and neuropsychological changes that accompany OFC atrophy in FTD and argue that phylogenetically new neurons found in this region, called von Economo neurons, are selectively vulnerable in FTD.

Responses of neurons in the medial temporal lobe during encoding and recognition of face-scene pairs.

Associations between co-occurring stimuli are formed in the medial temporal lobe (MTL). Here, we recorded from 508 single and multi-units in the MTL while participants learned and retrieved associations between unfamiliar faces and unfamiliar scenes. Participant's memories for the face-scene pairs were later tested using cued recall and recognition tests. The results show that neurons in the parahippocampal cortex are most likely to respond with changes from baseline firing to these stimuli during both encoding and recognition, and this region showed the greatest proportion of cells showing differential responses depending on the phase of the task. Furthermore, we found that cells in the parahippocampal cortex that responded during both encoding and recognition were more likely to show decreases from baseline firing than cells that were only recruited during recognition, which were more likely to show increases in firing. Since all stimuli shown during recognition were familiar to the patients, these findings suggest that with familiarity, cell responses become more sharply tuned. No neurons in this region, however, were found to be affected by recombining face/scene pairs. Neurons in other MTL regions, particularly the hippocampus, were sensitive to stimulus configurations. Thus, the results support the idea that neurons in the parahippocampal cortex code for features of stimuli and neurons in the hippocampus are more likely to represent their specific configurations.

Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.

We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher order visual processes due to neural degeneration. The value we find for H of 0.57 shows that the gaze dynamics during free viewing of fractal images are consistent with a random walk process with persistent movements. Our research suggests the human visual system may have a common strategy that drives the dynamics of human gaze during exploration.

Memory for famous people in patients with unilateral temporal lobe epilepsy and excisions.

Memory for famous individuals was assessed by the use of a recognition test in which participants first made familiarity judgments, followed by forced-choice decisions to specific probes for identity. Patients with temporal lobe epilepsy (TLE) or excisions, 12 left hemisphere and 12 right hemisphere, and 18 control participants identified famous figures across 3 decades (1970s-1990s). Only patients with right TLE were impaired at familiarity judgments of faces; this deficit was evident only for the most recent decades. Both groups of patients, however, were impaired at naming famous faces and at providing semantic information about famous people. These findings suggest the integrity of temporal structures in both hemispheres is critical for retrieval of detailed semantic information about famous individuals.

Relational integration, inhibition, and analogical reasoning in older adults.

The difficulty of reasoning tasks depends on their relational complexity, which increases with the number of relations that must be considered simultaneously to make an inference, and on the number of irrelevant items that must be inhibited. The authors examined the ability of younger and older adults to integrate multiple relations and inhibit irrelevant stimuli. Young adults performed well at all but the highest level of relational complexity, whereas older adults performed poorly even at a medium level of relational complexity, especially when irrelevant information was presented. Simulations based on a neurocomputational model of analogical reasoning, Learning and Inference with Schemas and Analogies (LISA), suggest that the observed decline in reasoning performance may be explained by a decline in attention and inhibitory functions in older adults.

Positive clinical neuroscience: explorations in positive neurology.

Disorders of the brain and its sensory organs have traditionally been associated with deficits in movement, perception, cognition, emotion, and behavior. It is increasingly evident, however, that positive phenomena may also occur in such conditions, with implications for the individual, science, medicine, and for society. This article provides a selective review of such positive phenomena--enhanced function after brain lesions, better-than-normal performance in people with sensory loss, creativity associated with neurological disease, and enhanced performance associated with aging. We propose that, akin to the well-established field of positive psychology and the emerging field of positive clinical psychology, the nascent fields of positive neurology and positive neuropsychology offer new avenues to understand brain-behavior relationships, with both theoretical and therapeutic implications.

Visual search patterns in semantic dementia show paradoxical facilitation of binding processes.

While patients with Alzheimer's disease (AD) show deficits in attention, manifested by inefficient performance on visual search, new visual talents can emerge in patients with frontotemporal lobar degeneration (FTLD), suggesting that, at least in some of the patients, visual attention is spared, if not enhanced. To investigate the underlying mechanisms for visual talent in FTLD (behavioral variant FTD [bvFTD] and semantic dementia [SD]) patients, we measured performance on a visual search paradigm that includes both feature and conjunction search, while simultaneously monitoring saccadic eye movements. AD patients were impaired relative to healthy controls (NC) and FTLD patients on both feature and conjunction search. BvFTD patients showed less accurate performance only on the conjunction search task, but slower response times than NC on all three tasks. In contrast, SD patients were as accurate as controls and had faster response times when faced with the largest number of distracters in the conjunction search task. Measurement of saccades during visual search showed that AD patients explored more of the image, whereas SD patients explored less of the image before making a decision as to whether the target was present. Performance on the conjunction search task positively correlated with gray matter volume in the superior parietal lobe, precuneus, middle frontal gyrus and superior temporal gyrus. These data suggest that despite the presence of extensive temporal lobe degeneration, visual talent in SD may be facilitated by more efficient visual search under distracting conditions due to enhanced function in the dorsal frontoparietal attention network.

Multimodal cuing of autobiographical memory in semantic dementia.

OBJECTIVE: Individuals with semantic dementia (SD) have impaired autobiographical memory (AM), but the extent of the impairment has been controversial. According to one report (Westmacott, Leach, Freedman, & Moscovitch, 2001), patient performance was better when visual cues were used instead of verbal cues; however, the visual cues used in that study (family photographs) provided more retrieval support than do the word cues that are typically used in AM studies. In the present study, we sought to disentangle the effects of retrieval support and cue modality. METHOD: We cued AMs of 5 patients with SD and 5 controls with words, simple pictures, and odors. Memories were elicited from childhood, early adulthood, and recent adulthood; they were scored for level of detail and episodic specificity. RESULTS: The patients were impaired across all time periods and stimulus modalities. Within the patient group, words and pictures were equally effective as cues (Friedman test; χ² = 0.25, p = .61), whereas odors were less effective than both words and pictures (for words vs. odors, χ² = 7.83, p = .005; for pictures vs. odors, χ² = 6.18, p = .01). There was no evidence of a temporal gradient in either group (for patients with SD, χ² = 0.24, p = .89; for controls, χ² < 2.07, p = .35). CONCLUSIONS: Once the effect of retrieval support is equated across stimulus modalities, there is no evidence for an advantage of visual cues over verbal cues. The greater impairment for olfactory cues presumably reflects degeneration of anterior temporal regions that support olfactory memory.

Advances in memory research: single-neuron recordings from the human medial temporal lobe aid our understanding of declarative memory.

PURPOSE OF REVIEW: To gain a complete understanding of how the brain functions, both in illness and good health, data from multiple levels of analysis must be integrated. Technical advances have made direct recordings of neuronal activity deep inside the human brain tractable, providing a rare glimpse into cellular processes during long-term memory formation. Recent findings using intracranial recordings in the medial temporal lobe inform current neural network models of memory, and may lead to a more comprehensive understanding of the neural basis of memory-related processes. RECENT FINDINGS: These recordings have shown that cells in the hippocampus appear to support declarative learning by distinguishing novel and familiar stimuli via changes in firing patterns. Some cells with highly selective and invariant responses have also been described, and these responses seem to represent abstract concepts such as identity, rather than superficial perceptual features of items. Importantly, however, both selective and globally responsive cells are capable of changing their preferred stimulus depending on the conscious demands of the task. SUMMARY: Firing patterns of human medial temporal lobe neurons indicate that cells can be both plastic and stable in terms of the information that they code; although some cells show highly selective and reproducible excitatory responses when presented with a familiar object, other cells change their receptive fields in line with changes in experience and the cognitive environment.