Oliver H. Turnbull

Object Recognition without Knowledge of Object Orientation

Several theories have been proposed to explain our ability to recognise objects from a number of viewpoints. Orientation-dependent accounts emphasize the position of the object relative to the viewer, while orientation-independent accounts (e.g. Marr) rely on descriptions of an objects component parts relative to its principal axis of elongation. An opportunity to compare the merit of these theories has arisen in a patient (L.G.) who had a rare neuropsychological sign in which knowledge of the canonical upright of object drawings was profoundly disrupted. Such orientation errors were evident in her drawings from memory and to copy, and in an orientation-matching task. In a critical experiment she showed a deficit in providing the canonical upright of individual object drawings that was independent of any difficulty in object recognition. The implications of these data for theories of object recognition are discussed.

Implicit awareness of deficit in anosognosia? An emotion-based account of denial of deficit

Most currently accepted models of anosognosia focus on disorders of body representation, or a disturbance of emotion systems, but struggle to explain the diverse range of findings of the phenomenon. Though currently unfashionable, there is a diverse body of recent evidence which suggests that anosognosics have “implicit” awareness of their deficit – and that their denial is motivated by the aversive emotional consequences that would accompany full awareness. This argument that has recently been supported by the work of Ramachandran and others, including the suggestion by Solms and Kaplan-Solms that such knowledge of the deficit can occasionally reach consciousness, causing great (albeit temporary) distress to the patient. The present study investigated the original Solms and Kaplan-Solms session notes, for both anosognosic and non-anosognosic patients, using a method of blind rating of the case material. The pattern of explicit emotional experience was the same for both left and right hemisphere patients, but anosognosic patients were more likely to express emotion that related to subjects other than their disability or its implications. They were also more likely to experience emotional breakdowns at moments that were preceded by talk of loss –even if the cause of such loss was apparently unrelated to their hemiparesis. These findings of implicit awareness are entirely compatible accounts of anosognosia that stress the patient’s implicit awareness of their disorder, and the importance of issues of emotion and motivation in the generation and maintenance of their false belief.

Failure to discriminate between mirror-image objects: A case of viewpoint-independent object recognition?

Abstract There is evidence from the literature, based on normal human subjects and on animals, to suggest that some stages of the object recognition process code images in a manner that carries no enantiomorphy (i.e. mirror-image) information. A patient, RJ, is reported who is severely impaired in discriminating between mirror-image objects. He can successfully discriminate between objects that differ by a minor structural alteration, or by rotation in the picture-plane. He can also discriminate between mirror-image words. In addition, RJ can reliably recognize objects, including those used in the mirror-image task. Various explanations for these unusual findings are discussed, the most probable of which is that RJ lacks a suitable egocentric reference frame, or is unable to compare such a reference frame with the type of representation employed for the purposes of object recognition.

Attention and emotion in anosognosia: evidence of implicit awareness and repression?

Accounts of anosognosia for hemiplegia have long suggested some implicit knowledge of deficit, where lack of awareness is driven by the emotionally-aversive consequences of bringing deficit-related thoughts to consciousness. The present study investigates this issue using an attentional-capture paradigm, presenting words associated with hemiplegia-related deficit. As anticipated, non-anosognosics showed reduced latencies (i.e., facilitation) for emotionally threatening words. In striking contrast, anosognosics showed increased latencies (i.e., interference), a finding which supports the claim of implicit awareness. The effect appears to be due to newly-learned associations to disability-related words: where anosognosics show a pattern of performance previously described as repression.

Preserved complex emotion-based learning in amnesia

An important role for emotion in decision-making has recently been highlighted by disruptions in problem solving abilities after lesion to the frontal lobes. Such complex decision-making skills appear to be based on a class of memory ability (emotion-based learning) that may be anatomically independent of hippocampally mediated episodic memory systems. There have long been reports of intact emotion-based learning in amnesia, arguably dating back to the classic report of Claparede. However, all such accounts relate to relatively simple patterns of emotional valence learning, rather than the more complex contingency patterns of emotional experience, which characterise everyday life. A patient, SL, who had a profound anterograde amnesia following posterior cerebral artery infarction, performed a measure of complex emotion-based learning (the Iowa Gambling Task) on three separate occasions. Despite his severe episodic memory impairment, he showed normal levels of performance on the Gambling Task, at levels comparable or better than controls-including learning that persisted across substantial periods of time (weeks). Thus, emotion-based learning systems appear able to encode, and sustain, more sophisticated patterns of valence learning than have previously been reported.

Assessing the Dream-Lag Effect for REM and NREM Stage 2 Dreams

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5–7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.

Loss of stored knowledge of object structure: Implications for 'category-specific' deficits.

Following a right-hemisphere lesion, the patient SM had impaired object recognition, with good elementary visual abilities, and could derive information about object structure. He was also impaired on all tasks tapping stored structural knowledge, even when tested in the verbal modality. This suggests that SM has a disorder affecting stored knowledge of object structure, though he remains able to assemble novel structural descriptions. His object recognition ability also appeared significantly worse for non-living things. By contrast, existing models relating to stored knowledge would predict that SM would show greater impairment with living things. We argue that SM’s deficit reflects the loss of a type of structural knowledge that relates to the “within-item structural diversity” of items. It is argued that living things show less structural variation than objects in the natural world, and might arguably be easier to recognise, because the image of the to-be-recognised object would be similar to the stored representation. Hence, a deficit affecting this aspect of stored knowledge would differentially impact upon non-living things. This argument receives confirming independent support from the finding that normal subjects ratings for the within-item structural diversity of visual stimuli are (unlike other “critical” variables) significant predictors of SM’s naming performance.

What Is Neuropsychoanalysis

This article briefly surveys the interdisciplinary field of neuroscience and psychoanalysis (“neuropsychoanalysis”) and also addresses some of the criticisms that the field has encountered. First, the article reviews the historical foundations of neuropsychoanalysis, including both theoretical and technical questions of whether an interdiscipline is appropriate. Second, it discusses the philosophical foundations of the field, including the position of dual-aspect monism. Third, the article examines the scientific foundations, with a discussion of whether analytic work with neurological patients represents an optimal point of contact between the disciplines. Finally, the article engages with the issue of what neuropsychoanalysis is not, covering issues such as “speculation versus empirical research,” and the question of whether neuropsychoanalysis represents a new “school” of psychoanalysis.

The Pleasantness of False Beliefs: An Emotion-based Account of Confabulation

This paper reports an empirical reinvestigation of data collected by Karen Kaplan-Solms and Mark Solms. It focuses on neurological patients with medial frontal lesions, who exhibit striking and strongly held false beliefs, generally referred to as confabulations. Most accounts of the cause of confabulations are cognitive, focusing on the importance of memory or executive deficits. This study attempts to test the underinvestigated suggestion that confabulations may not be emotionally neutral, having a (“wish-fulfillment”) bias that shapes the patient’s perception of reality in a more affectively positive direction. When recast in psychoanalytic terms, this proposal is consistent with Kaplan-Solms and Solms’s (2000) claim about the role of Freud’s (1915) special characteristics of the system unconscious in understanding confabulation. The present study tests this claim by a quantitative investigation of the process notes from which the Kaplan-Solms and Solms account was generated. We replicated our previous claim that confabulations show a positive emotional bias, finding that the vast majority (79%) of confabulations occurred when the patients were in a low mood state and, simultaneously, when the confabulations were affectively positive. The possible importance of these findings, and a range of important methodological issues in relation to these data, are discussed.

The dynamics of mood and coping in bipolar disorder: longitudinal investigations of the inter-relationship between affect, self-esteem and response styles.

Background Previous research has suggested that the way bipolar patients respond to depressive mood impacts on the future course of the illness, with rumination prolonging depression and risk-taking possibly triggering hypomania. However, the relationship over time between variables such as mood, self-esteem, and response style to negative affect is complex and has not been directly examined in any previous study – an important limitation, which the present study seeks to address. Methods In order to maximize ecological validity, individuals diagnosed with bipolar disorder (N = 48) reported mood, self-esteem and response styles to depression, together with contextual information, up to 60 times over a period of six days, using experience sampling diaries. Entries were cued by quasi-random bleeps from digital watches. Longitudinal multilevel models were estimated, with mood and self-esteem as predictors of subsequent response styles. Similar models were then estimated with response styles as predictors of subsequent mood and self-esteem. Cross-sectional associations of daily-life correlates with symptoms were also examined. Results Cross-sectionally, symptoms of depression as well as mania were significantly related to low mood and self-esteem, and their increased fluctuations. Longitudinally, low mood significantly predicted rumination, and engaging in rumination dampened mood at the subsequent time point. Furthermore, high positive mood (marginally) instigated high risk-taking, and in turn engaging in risk-taking resulted in increased positive mood. Adaptive coping (i.e. problem-solving and distraction) was found to be an effective coping style in improving mood and self-esteem. Conclusions This study is the first to directly test the relevance of response style theory, originally developed to explain unipolar depression, to understand symptom changes in bipolar disorder patients. The findings show that response styles significantly impact on subsequent mood but some of these effects are modulated by current mood state. Theoretical and clinical implications are discussed.