scholarly journals Evidence for normal novel object recognition abilities in developmental prosopagnosia

2020 ◽  
Author(s):  
Regan Fry ◽  
Jeremy Bennet Wilmer ◽  
Isabella Xie ◽  
Mieke Verfaellie ◽  
Joseph DeGutis

The question of the face specificity of recognition deficits in prosopagnosia is fundamental to the organization of high-level visual processing and memory and has been vigorously debated numerous times over the last 20 years. This debate was recently revived in developmental prosopagnosics (DPs) by a meta-analysis reporting that a large percentage of DPs (ranging from 22-80%) have mild to major object recognition deficits (Geskin & Behrmann, 2017). Subsequent studies have also shown significantly lower DP group-level object recognition performance. However, previous investigations measuring object recognition have largely used familiar objects (e.g., cars) where performance may depend on object-specific experience, leaving the question open as to whether DPs would perform similarly when the stimuli are completely unfamiliar objects. To investigate this, in the current study we tested 30 DPs and 30 matched controls on a novel object memory test (NOMT Ziggerins) and the Cambridge Face Memory Test (CFMT). DPs were impaired on the CFMT but performed similarly to controls on the NOMT. We also compared DP NOMT performance to a larger matched sample of 274 web-based controls and found no difference in accuracy or reaction time. Individual analyses demonstrated that only one DP reached major impairment in object recognition on the NOMT, an impairment rate no different from that in either control group. Together, these results demonstrate essentially normal object recognition in DPs for a class of novel objects that serves as a powerful index for broader novel object recognition capacity. These results raise the possibility that DPs do not have object recognition deficits per se, but rather may have a decreased capacity to benefit from their experience with highly familiar object categories.

2020 ◽  
Vol 7 (9) ◽  
pp. 200988
Author(s):  
Regan Fry ◽  
Jeremy Wilmer ◽  
Isabella Xie ◽  
Mieke Verfaellie ◽  
Joseph DeGutis

The issue of the face specificity of recognition deficits in developmental prosopagnosia (DP) is fundamental to the organization of high-level visual memory and has been increasingly debated in recent years. Previous DP investigations have found some evidence of object recognition impairments, but have almost exclusively used familiar objects (e.g. cars), where performance may depend on acquired object-specific experience and related visual expertise. An object recognition test not influenced by experience could provide a better, less contaminated measure of DPs' object recognition abilities. To investigate this, in the current study we tested 30 DPs and 30 matched controls on a novel object memory test (NOMT Ziggerins) and the Cambridge Face Memory Test (CFMT). DPs with severe impairment on the CFMT showed no differences in accuracy or reaction times compared with controls on the NOMT. We found similar results when comparing DPs with a larger sample of 274 web-based controls. Additional individual analyses demonstrated that the rate of object recognition impairment in DPs did not differ from the rate of impairment in either control group. Together, these results demonstrate unimpaired object recognition in DPs for a class of novel objects that serves as a powerful index for broader novel object recognition capacity.


2019 ◽  
Author(s):  
Jorge M Ferreira ◽  
Ana M Valentim

AbstractConcerns have been raised about how deeply patients are anaesthetized, and the effects that different depths of anaesthesia may have after recovery. In order to study the anaesthetic drugs per se, and to eliminate the effect of clinical variables, several animal studies have been published. Isoflurane induced transient deficits on spatial memory at low concentrations, affecting the hippocampus. However, the influence of different concentrations of isoflurane on non-spatial memory still needs clarification. Thus, our aim was to study the effects of different depths of anaesthesia (1% and 2% isoflurane) on a non-spatial memory task, the object recognition test, in C57BL/6 adult mice.Twenty-eight 2-month-old C57BL/6 male mice were habituated to the test arena of the object recognition test for 10 min each day over 2 days before anaesthesia. Mice were then randomly allocated in different treatment groups: 1% or 2%, anaesthetized with 1% or 2% of isoflurane, respectively, for 1 h or the control group, which was not anaesthetised. Twenty-four hours after anaesthesia, the animals were placed in an arena with two identical objects and allowed to explore for 10 min-Sample Trial. One hour later, mice were allowed to explore the arena for 10 min in the presence of one of the objects presented in the previous trial (familiar object) and a novel object - Choice Trial. The time spent exploring each object was evaluated by a blinded analysis. The recognition of one object as familiar was detected based on a higher level of exploration of the novel object.Animals that were anaesthetized previously with 2% isoflurane performed at control levels, indicating the recognition of a familiar object in the object recognition task; this contrasted with the results of the group that was anaesthetized with 1% isoflurane.Lighter (1%) rather than deeper (2%) isoflurane anaesthesia may affect non-spatial memory in C57BL/6 male mice. Our results raise awareness of the need for careful consideration of the depth of anaesthesia used, especially the use of light isoflurane anaesthesia, which is often chosen to provide animal immobilization during non-invasive procedures.


2017 ◽  
Vol 50 (6) ◽  
pp. 1701456 ◽  
Author(s):  
David Gozal ◽  
Abdelnaby Khalyfa ◽  
Zhuanghong Qiao ◽  
Isaac Almendros ◽  
Ramon Farré

Intermittent hypoxia is one of the major perturbations of sleep-disordered breathing and has been causally implicated in neurocognitive deficits. However, the reversibility of such deficits is unclear.Male C57BL/6J mice were exposed to either intermittent hypoxia or room air for 3–240 days, and then half were randomly selected and allowed to recover in normoxic conditions for the same duration of the previous exposure. A novel object recognition (NOR) test was performed.NOR performance was stable over time in room air. Intermittent hypoxia induced significant reductions in recognition index that progressed over the first 45 days and stabilised thereafter. Normoxic recovery of recognition index was essentially complete and indistinguishable from room air in mice exposed to shorter intermittent hypoxia times (<90 days). However, significant residual deficits emerged after normoxic recovery following prolonged intermittent hypoxia exposures (p<0.01). In addition, gradual attenuation of the magnitude of recovery in recognition index occurred with increasingly longer intermittent hypoxia exposures (MANOVA p<0.0001).Intermittent hypoxia during the resting period reduces NOR performance in a time-dependent fashion. Reversal of NOR performance deficits is unlikely after prolonged intermittent hypoxia duration. These findings suggest that early recognition of sleep apnoea and effective treatment are critical for restoration of the adverse cognitive effects of the disease.


2018 ◽  
Vol 4 (1) ◽  
pp. 7-11
Author(s):  
NISFA HANIM ◽  
SALMAH WIDYASTUTI ◽  
ACHMAD ALFIYAN ◽  
MUHAMMAD AZHARI AKBAR ◽  
BERRY JULIANDI

This research aimed to confirm the tendency of mice to novel object, effect of exercise (in running-wheel) toward memory of mice and to test tendency of mice in avoiding predator signal in novel object. Novel object recognition test (NORT) used to test the memory the day after acquisition phase (NORT I) and memory one week after exercise was given (running-wheel) (NORT II). The result showed that there was no tendency of mice in exploring toward novel object in both NORT I and NORT II. This might happen because the complexity of familiar object higher than novel object, so the familiar object could accommodate more activities. Exercise using running-wheel in mice had an effect on memory, it could be seen in decreasing duration of object exploration time from NORT I to NORT II. There was no tendency in avoiding predator’s signal on novel object which was attached by urine addition (odor signal).


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Elham Saghaei ◽  
Shakiba Nasiri Boroujeni ◽  
Parvin Safavi ◽  
Zeinab Borjian Boroujeni ◽  
Elham Bijad

Background and Aim. Numerous reports have indicated that dealing with stressors in life is a main risk factor for the occurrence and progression of cognitive and memory impairment. Available treatments such as benzodiazepine and antidepressants address only certain aspects of this stress disorder and have numerous side effects. The present study was aimed at investigating the effect of diosmetin, as a flavonoid compound with potent antioxidant and anti-inflammatory effects, on cognitive impairment and chronic stress memory. Materials and Methods. In the present experimental study, male NMRI mice were exposed to chronic unpredictable mild stress (CUMS) paradigm for 35 days. Diosmetin (at doses of 10, 20, and 40 mg/kg. i.p.) or diosmetin solvent (normal saline + DMSO, 1 ml/kg; i.p.) was administered 30 min before stress induction. After 28 days, memory and cognitive performance were assessed by shuttle box and novel object recognition tests. Finally, antioxidant capacity (FRAP) and malondialdehyde (MDA) level of serum and brain, and serum corticosterone level were evaluated. Results. Behavioral tests showed that CUMS significantly reduced the secondary latency in passive avoidance memory test and diagnosis index in novel object recognition test compared to the control group ( P < 0.001 ), whereas treatment with diosmetin (20 and 40 mg/kg) significantly improved memory performance in the two tests ( P < 0.001 ). In addition, diosmetin (40 mg/kg) could pronouncedly suppress increase in serum corticosterone levels, reduction in antioxidant capacity, and production of excess MDA caused by CUMS compared to the control group ( P < 0.01 , P < 0.001 , and P < 0.001 , respectively). Conclusion. Chronic stress can impair memory and cognition and treatment with diosmetin can partly improve this disorder in male mice by increasing the antioxidant capacity of brain tissue and serum and improving serum corticosterone levels.


2021 ◽  
Vol 13 (2) ◽  
pp. 36-46
Author(s):  
A. T. Idris ◽  
A.M. Sunday ◽  
A.I. Ibrahim ◽  
O.N. James ◽  
A.K. Musa ◽  
...  

The study aimed to evaluate the effects of oral ingestion of hyoscyamine fraction of Daturastramonium seeds on the hippocampus in adult Wistar rats. Fresh seeds of D. stramonium were procured and fractionated using high-performance liquid chromatography (HPLC). Twenty-four healthy adult Wistar rats weighed 230±0.50 grams, were procured and divided equally into four groups for the experiment. The group one received an equivalent bodyweight of normal saline, while three other groups received 200, 400 and 800 mg/kgbwt of hyoscyamine fraction of D. stramonium respectively for three weeks. At the end of the experiment, the animals were subjected to memory test using Morris water maze (MWM) and Novel object recognition test (NORT) test paradigms. The data obtained were expressed as mean ± SEM and repeated measures ANOVA with Fisher’s multiple comparisons post-hoc tests were used to obtain mean differences using Minitab 17 (LLC., U.K.) statistical package software. P < 0.05  was considered statistically significant. There was a statistically significant increase in the exploration time (p = 0.031) and escape latency period (p < 0.001) in the novel object recognition and Morris water maze test between the groups in the treated compared to the control group. The CA3 region of the treated group showed significant neuronal lesions, cytoplasmic vacuolations, pyknosis and necrosis. . In conclusion, exposure to hyoscyamine fraction of D.stramonium at adulthood impaired memory in Wistar rats.  


2021 ◽  
Author(s):  
Ivonne Becker ◽  
Lihua Wang‐Eckhardt ◽  
Julia Lodder‐Gadaczek ◽  
Yong Wang ◽  
Agathe Grünewald ◽  
...  

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