Behavioural and cognitive mechanisms of Developmental Topographical Disorientation.

Individuals affected by Developmental Topographical Disorientation (DTD) get lost on a daily basis, even in the most familiar of surroundings such as their neighbourhood, the building where they have worked for many years, and, in extreme cases, even in their own homes. Individuals with DTD report a lifelong selective inability to orient despite otherwise well-preserved general cognitive functions, and the absence of any acquired brain injury or neurological condition, with general intelligence reported to be within the normal range. To date, the mechanisms underlying such a selective developmental condition remain unknown. Here, we report the findings of a 10-year-long study investigating the behavioural and cognitive mechanisms of DTD in a large sample of 1211 cases. We describe the demographics, heritability pattern, self-reported and objective spatial abilities, and some personality traits of individuals with DTD as compared to a sample of 1624 healthy controls; importantly, we test the specific hypothesis that the presence of DTD is significantly related to the inability of the individuals to form a mental representation of the spatial surroundings (i.e., a cognitive map). We found that individuals with DTD reported relatively greater levels of neuroticism and negative affect, and rated themselves more poorly on self-report measures of memory and imagery skills related to objects, faces, and places. While performing interactive tasks, as a group, the individuals with DTD performed slightly worse on a scene-based perspective-taking task, and, notably struggled to solve tasks that demand the generation and use of a cognitive map. These novel findings help define the phenotype of DTD, and lay the foundation for future studies of the neurological and genetic mechanisms of this lifelong condition.

Demographic characteristics and delayed neurological sequelae risk factors in carbon monoxide poisoning.

AIM: Carbon monoxide (CO) is a colorless, odorless gas and tasteless. CO poisoning (COP) is one of the most frequently encountered inhalation poisonings. The most common cause of morbidity in COP is delayed neurological sequelae (DNS). DNS is the occurrence of neuropsychiatric findings within 2-240 days after discharge of patients with COP and there are no definitive diagnostic criteria. The aim of our study is; to determine the risk factors and incidence of DNS. METHOD: Our study is a retrospective, observational study. Patients with the diagnosis of COP in the emergency department between 2015 and 2016 were included in the study. Patients age, gender, findings in the initial physical examination (PE) and neurological examination (NE), blood carboxyhemoglobin (COHb) level, relation between hyperbaric oxygen (HBO) treatment and DNS were assessed. RESULTS: Total of 72 patients were included in the study. Mean age was 33.43 ±â€¯20.89. It was determined that pathological findings in the initial NE are a significant predictive factor for DNS (Odds ratio 18.600, p:0.004). Significant relation between NE and HBO treatment was present (p:00.1). There was no statistically significant relationship between initial COHb level and receiving HBO treatment (p:0.9). Median COHb level of patients with DNS was 30 (min:10, max: 43), median COHb level of patients without DNS was 25 (min:10, max:44) and there was no statistically significant relationship between the two groups according to COHb levels (p:0.7). CONCLUSION: Pathological findings in the initial neurological examination had a predictive value for delayed neurological sequelae in patients with carbon monoxide poisoning.

Auditory Verbal Working Memory Load Effects on a Simulator-Induced Spatial Disorientation Event.

INTRODUCTION: Working memory is an essential executive function for flying an aircraft and its limitations may jeopardize flight safety. This function is particularly critical when pilots have to struggle with spatial disorientation (SD) cues. This research aimed to assess the combined effect of the auditory N-back task (NBT) and simulator-induced SD cues on pilots' flight performance.METHODS: Using an SD simulator, 39 male military pilots (control N = 20; age M = 31.6; SD = 8.22, experimental N = 19; age M = 26.9; SD = 8.67) were exposed to 12 flight sequences, where 6 contained an SD conflict-3 with vestibular illusions and 3 with visual illusions. Additionally, the pilots from the experimental group were asked to perform an auditory NBT involving sound stimuli (the sequential letter memory task) as they performed during oriented and disoriented flight conditions.RESULTS: Pilots' flight performance from the NBT group were significantly worse than the control group in the approach and landing profiles involving visual illusions (for both nonconflict and conflict flight), and in the profile involving the false horizon illusion (only for the conflict flight). No increase in a pilot's susceptibility to SD was observed with any other profiles.DISCUSSION: The current study provides support that pilots' cognitive workload can negatively impact flight performance. Pilots are not always aware of altered flight parameters, which may indicate that they have lost spatial orientation, mainly as a result of visual illusion. If problems occur in maintaining proper flight parameters, pilots should direct all available mental resources to regain their orientation and withdraw from any other parallel tasks.Lewkowicz R, Strózak P, Balaj B, Francuz P. Auditory verbal working memory load effects on a simulator-induced spatial disorientation event. Aerosp Med Hum Perform. 2019; 90(6):531-539.

Where Am I? A new case of developmental topographical disorientation.

Recently, developmental topographical disorientation (DTD) was described (Bianchini et al., 2010, J Clin Exp Neuropsychol, 20, 807-27; Iaria & Barton, 2010, Exp Brain Res, 206, 189-96; Iaria, Bogod, Fox, & Barton, 2009, Neuropsychologia, 47, 30-40) as a navigational deficit in the absence of neurological or psychiatric disorders. Here, we reported the case of a healthy subject who presented this disorder. Dr. WAI was a 29-year-old right-handed man with normal development and no clinical history of neurological or psychiatric diseases who was affected by a very pervasive topographical orientation and navigational disorder. A neuroradiological exam confirmed the absence of structural and anatomical alterations of the brain. Dr. WAI was submitted to an extensive neuropsychological examination and to a battery of tests specifically developed to assess developmental topographical disorder. Using this battery, we analysed Dr. WAI's acquisition of navigational information and re-orientation processes. He showed severe DTD accompanied by deficits of different cognitive processes directly or indirectly involved in navigational skills. Dr. WAI showed a deficit in developing cognitive maps, already found in previous cases, plus difficulties in evaluating distances and computing metric environmental features. He represents a further confirmation of the existence of DTD suggesting dissociations within the disorder related to the level of development of the ability to build cognitive maps and the association of different imagery deficits. Dr. WAI can help in shedding some light on the mechanisms underlying lack of development of navigational skills.

The role of embodied simulation in mental transformation of whole-body images: evidence from Parkinson's disease.

It has been repeatedly demonstrated that mentally performing an action and mentally transforming body-parts entail simulation of one's own body movements, consistent with predictions of embodied cognition theories. However, the involvement of embodied simulation in mental transformation of whole-body images is still disputed. Here, we assessed own body transformation in Parkinson's disease (PD) patients with symptoms most affecting the left or the right body side. PD patients were required to perform left-right judgments on front-facing or back-facing human figures, and a letter rotation task. Results demonstrated that PD patients were selectively impaired in judging the side of back-facing human figures corresponding to their own most affected side, but performed as well as healthy subjects on mental transformation of front-facing bodies and on letter rotation. These findings demonstrate a parallel impairment between motor and mental simulation mechanisms in PD patients, thus highlighting the specific contribution of embodied cognition to mental transformation of whole-body images.

Topographical disorientation: towards an integrated framework for assessment.

Topographical disorientation, the inability to find one's way in large-scale environments, is a relatively common disorder. However, there are relatively few cognitive neuropsychological studies that investigate the nature of topographical cognition. Theoretical progress has been hindered by a number of factors including: terminological confusion; lack of theoretically driven assessment; the use of broad classifications for the nature of underlying impairments; and an ongoing failure to examine topographical skills in real-life settings. As a result, there is currently no well-established or widely accepted theoretical framework encompassing all aspects of this multifaceted area of cognition. In addition, there is a relative paucity of published case studies that include a comprehensive, theoretically based assessment of topographical disorientation, and treatment of the disorder has received virtually no formal investigation (with the exception of Davis & Coltheart, 1999). Thus, the current paper focuses on the development of a broad framework for understanding topographical cognition that integrates a number of recent theories of topographical orientation and mental imagery (Farah, 1984; Kosslyn, 1980; Riddoch & Humphreys, 1989). The aim of the paper is to present a preliminary framework that can be used as a basis for further refinement and development of theoretical proposals, and be employed by clinicians as a starting point for assessment planning.

Auditory and visual spatial localization deficits following bilateral parietal lobe lesions in a patient with Balint's syndrome.

Lesion and electrophysiological studies indicate that the parietal lobes play a role in visual spatial attention and in computing the spatial coordinates of visual input. Fewer studies have investigated the role of the parietal lobe in auditory spatial processing, and an extensive comparison of visual and auditory spatial processing in humans with parietal lobe lesions has yet to be conducted. We have studied such localization abilities in a Balint's syndrome patient (RM) who has bilateral parietal lobe lesions. The results indicated that this patient had a significant deficit in both visual and auditory localization relative to age-matched controls. Unlike the controls, however, RM's auditory localization ability either matched or exceeded his visual localization ability depending on the task. Accordingly, RM exhibited "auditory capture," but not "visual capture" under conditions where control subjects showed the opposite pattern. These results are consistent with hypotheses that the parietal lobes are involved in creating multiple spatial representations and in shifting from one spatial reference point to another, but suggest that these parietal structures are not necessary for the integration of multiple sensory stimuli resulting in capture effects.

Alertness and clear thinking as characteristics of high naturally occurring autonomic nervous system arousal.

Studies of the effect of induced mood on the autonomic nervous system (ANS) suggested that naturally occurring mood might also covary with the ANS. Ss were 13 men and women aged 20 to 70. Fatigue, confusion, and depression were measured on the Profile of Mood States, while barometric pressure and the ANS indices of heart rate and body temperature were also recorded. Fatigue and confusion each showed negative relationships to both heart rate and body temperature. Barometric pressure showed a suggestively positive relationship to the mood of depression. Hypothalamic serotonin concentration was suggested as a central factor producing the covariations between the mood indices (alertness and clear thinking) and the ANS measures.