The Impact of COVID-19 Lockdown Measures and COVID-19 Infection on Cognitive Functions: A Review in Healthy and Neurological Populations.

The COVID-19 pandemic severely affected people's mental health all over the world. This review aims to present a comprehensive overview of the literature related to the effects of COVID-19 lockdown measures and COVID-19 infection on cognitive functioning in both healthy people and people with neurological conditions by considering only standardized tests. We performed a narrative review of the literature via two databases, PUBMED and SCOPUS, from December 2019 to December 2022. In total, 62 out of 1356 articles were selected and organized into three time periods: short-term (1-4 months), medium-term (5-8 months), and long-term (9-12 months), according to the time in which the tests were performed. Regardless of the time period, most studies showed a general worsening in cognitive performance in people with neurological conditions due to COVID-19 lockdown measures and in healthy individuals recovered from COVID-19 infection. Our review is the first to highlight the importance of considering standardized tests as reliable measures to quantify the presence of cognitive deficits due to COVID-19. Indeed, we believe that they provide an objective measure of the cognitive difficulties encountered in the different populations, while allowing clinicians to plan rehabilitation treatments that can be of great help to many patients who still, nowadays, experience post-COVID-19 symptoms.

How Has COVID-19 Impacted Our Language Use?

The COVID-19 pandemic has led to severe consequences for people's mental health. The pandemic has also influenced our language use, shaping our word formation habits. The overuse of new metaphorical meanings has received particular attention from the media. Here, we wanted to investigate whether these metaphors have led to the formation of new semantic associations in memory. A sample of 120 university students was asked to decide whether a target word was or was not related to a prime stimulus. Responses for pandemic pairs in which the target referred to the newly acquired metaphorical meaning of the prime (i.e., "trench"-"hospital") were compared to pre-existing semantically related pairs (i.e., "trench"-"soldier") and neutral pairs (i.e., "trench"-"response"). Results revealed greater accuracy and faster response times for pandemic pairs than for semantic pairs and for semantic pairs compared to neutral ones. These findings suggest that the newly learned pandemic associations have created stronger semantic links in our memory compared to the pre-existing ones. Thus, this work confirms the adaptive nature of human language, and it underlines how the overuse of metaphors evoking dramatic images has been, in part, responsible for many psychological disorders still reported among people nowadays.

A Standardized Prospective Memory Evaluation of the Effects of COVID-19 Confinement on Young Students.

The restriction imposed worldwide for limiting the spread of coronavirus disease 2019 (COVID-19) globally impacted our lives, decreasing people's wellbeing, causing increased anxiety, depression, and stress and affecting cognitive functions, such as memory. Recent studies reported decreased working memory (WM) and prospective memory (PM), which are pivotal for the ability to plan and perform future activities. Although the number of studies documenting the COVID-19 effects has recently blossomed, most of them employed self-reported questionnaires as the assessment method. The main aim of our study was to use standardized tests to evaluate WM and PM in a population of young students. A sample of 150 female psychology students was recruited online for the administration of two self-reported questionnaires that investigated psychological wellbeing (DASS-21), prospective, and retrospective memory (PRMQ). Subjects were also administered two standardized tests for WM (PASAT) and PM (MIST). We found increased anxiety, depression, and stress and decreased PM as measured by self-reports. The perceived memory failures agreed with the results from the standardized tests, which demonstrated a decrease in both WM and PM. Thus, COVID-19 restriction has strongly impacted on students' mental health and memory abilities, leaving an urgent need for psychological and cognitive recovery plans.

DUAL-tDCS Treatment over the Temporo-Parietal Cortex Enhances Writing Skills: First Evidence from Chronic Post-Stroke Aphasia.

The learning of writing skills involves the re-engagement of previously established independent procedures. Indeed, the writing deficit an adult may acquire after left hemispheric brain injury is caused by either an impairment to the lexical route, which processes words as a whole, to the sublexical procedure based on phoneme-to-grapheme conversion rules, or to both procedures. To date, several approaches have been proposed for writing disorders, among which, interventions aimed at restoring the sub-lexical procedure were successful in cases of severe agraphia. In a randomized double-blind crossover design, fourteen chronic Italian post-stroke aphasics underwent dual transcranial direct current stimulation (tDCS) (20 min, 2 mA) with anodal and cathodal current simultaneously placed over the left and right temporo-parietal cortex, respectively. Two different conditions were considered: (1) real, and (2) sham, while performing a writing task. Each experimental condition was performed for ten workdays over two weeks. After real stimulation, a greater amelioration in writing with respect to the sham was found. Relevantly, these effects generalized to different language tasks not directly treated. This evidence suggests, for the first time, that dual tDCS associated with training is efficacious for severe agraphia. Our results confirm the critical role of the temporo-parietal cortex in writing skills.

Spinal or cortical direct current stimulation: Which is the best? Evidence from apraxia of speech in post-stroke aphasia.

To date, new advances in technology have already shown the effectiveness of non-invasive brain stimulation and, in particular, of transcranial direct current stimulation (tDCS), in enhancing language recovery in post-stroke aphasia. More recently, it has been suggested that the stimulation over the spinal cord improves the production of words associated to sensorimotor schemata, such as action verbs. Here, for the first time, we present evidence that transpinal direct current stimulation (tsDCS) combined with a language training is efficacious for the recovery from speech apraxia, a motor speech disorder which might co-occur with aphasia. In a randomized-double blind experiment, ten aphasics underwent five days of tsDCS with concomitant treatment for their articulatory deficits in two different conditions: anodal and sham. In all patients, language measures were collected before (T0), at the end (T5) and one week after the end of treatment (F/U). Results showed that only after anodal tsDCS patients exhibited a better accuracy in repeating the treated items. Moreover, these effects persisted at F/U and generalized to other oral language tasks (i.e. picture description, noun and verb naming, word repetition and reading). A further analysis, which compared the tsDCS results with those collected in a matched group of patients who underwent the same language treatment but combined with tDCS, revealed no differences between the two groups. Given the persistency and severity of articulatory deficits in aphasia and the ease of use of tsDCS, we believe that spinal stimulation might result a new innovative approach for language rehabilitation.

Cognitive functions underlying prospective memory deficits: A study on traumatic brain injury.

This study investigates prospective memory (PM) deficits as well as the interplay between performance in executive functions (EFs), speed of processing, episodic memory and PM in traumatic brain injury (TBI), differentiating between time based and event based tasks. The Memory for Intentions Screening Test was administrated to a sample of 19 participants with TBI and 50 healthy controls. Tasks probing different EFs (i.e., shifting, updating/working memory, inhibition, and access to long term memory), speed of processing, and episodic memory were also administrated to the TBI group. PM deficits were found in participants with TBI compared to controls. In the role of EFs in PM, only tasks probing updating/working memory and access to the long-term memory showed to play a specific role in PM performance in TBI. However, while updating/working memory was related to both time and event based PM, access to the long term memory was associated to performance on time based PM task only. Speed of processing and retrospective memory abilities do not seem to play a specific role in PM deficit in TBI. Our results provide a better understanding of the PM deficit in TBI, which may contribute to improve existing rehabilitation programs for individuals with TBI.

Stairways to the brain: Transcutaneous spinal direct current stimulation (tsDCS) modulates a cerebellar-cortical network enhancing verb recovery.

It has long been assumed that the language function is hierarchically organized into specific cortical areas. Here, for the first time, we present direct evidence that the spinal cord takes part in language processing. In a randomized-double blind design, sixteen aphasics underwent a language treatment combined with transcutaneous spinal direct current stimulation (tsDCS). During the treatment, each subject received tsDCS (20 min, 2 mA) over the thoracic vertebrae (IX-X vertebrae) in two different conditions: (1) anodal, and (2) sham while performing a verb naming task. Each experimental condition was run in five consecutive daily sessions over two weeks. Before and after each condition, all patients underwent a resting state functional magnetic resonance imaging (rs-fMRI). After anodal tsDCS, significant functional connectivity changes were found in a cerebellar-cortical network recruiting regions such as the left cerebellum, the right parietal and premotor cortex known to be also involved in action-related verb processing. Indeed, this increase of connectivity significantly correlated with the greatest amount of improvement found in verb naming. In line with our experimental data, we also found a greater improvement after anodal tsDCS also on untreated items of the language test but only on tasks which required the use of verbs, such as verb naming and picture description. No significant changes were found in noun naming. Thus, this evidence emphasizes, for the first time, that the neural response due to tsDCS combined with language treatment changes during the course of recovery by enhancing activity into cortical regions which influence verb processing.

The Tower of London (ToL) in Italy: standardization of the ToL test in an Italian population.

Deficit in planning and problem-solving, affecting a wide range of neuropsychological patients, has been widely investigated using the Tower of London (ToL) test, as developed by Shallice (Philos Trans R Soc Lond Ser B Biol Sci 298:199-209, 1). The ToL taps on several executive functions (EF), such as planning, time for planning or rule breaks, which may be usefully indexed by different ToL measurements. However, in its original version, the different aspects involved in ToL are not evaluated in a specific way.Here, we report the standardization of the ToL, on 896 individuals aged 15-86 years, taking in account individual factors (i.e. gender, age, years of education) which may affect performances on ToL. We computed several indexes on the ToL including score, planning and execution times, perseverations, rule breaks and self-monitoring. We found that these indexes were affected by individual factors such as gender, age and education. Present results not only provide extensive normative data according to gender, as well as different age and education ranges, but also represent a very useful instrument for a more fine-grained diagnosis of EF deficits in a wide range of neuropsychological patients, including traumatic brain injury and brain-damaged patients, as well as Alzheimer's disease and Parkinson's disease patients.

Persistence of Gender Related-Effects on Visuo-Spatial and Verbal Working Memory in Right Brain-Damaged Patients.

The aim of the present study was to verify if gender differences in verbal and visuo-spatial working memory would persist following right cerebral lesions. To pursue our aim we investigated a large sample (n. 346) of right brain-damaged patients and healthy participants (n. 272) for the presence of gender effects in performing Corsi and Digit Test. We also assessed a subgroup of patients (n. 109) for the nature (active vs. passive) of working memory tasks. We tested working memory (WM) administering the Corsi Test (CBT) and the Digit Span (DS) using two different versions: forward (fCBT and fDS), subjects were required to repeat stimuli in the same order that they were presented; and backward (bCBT and bDS), subjects were required to repeat stimuli in the opposite order of presentation. In this way, passive storage and active processing of working memory were assessed. Our results showed the persistence of gender-related effects in spite of the presence of right brain lesions. We found that men outperformed women both in CBT and DS, regardless of active and passive processing of verbal and visuo-spatial stimuli. The presence of visuo-spatial disorders (i.e., hemineglect) can affect the performance on Corsi Test. In our sample, men and women were equally affected by hemineglect, therefore it did not mask the gender effect. Generally speaking, the persistence of the men's superiority in visuo-spatial tasks may be interpreted as a protective factor, at least for men, within other life factors such as level of education or kind of profession before retirement.

Women outperform men in remembering to remember.

The study of gender differences in prospective memory (i.e., remembering to remember) has received modest attention in the literature. The few reported studies investigating either subjective or objective evaluations of prospective memory have shown inconsistent data. In this study, we aimed to verify the presence of gender differences during the performance of an objective prospective memory test by considering the weight of specific variables such as length of delay, type of response, and type of cue. We submitted a sample of 100 healthy Italian participants (50 men and 50 women) to a test expressly developed to assess prospective memory: The Memory for Intentions Screening Test. Women performed better than men in remembering to do an event-based task (i.e., prompted by an external event) and when the task required a physical response modality. We discuss the behavioural differences that emerged by considering the possible role of sociological, biological, neuroanatomical, and methodological variables.

Looking for the compass in a case of developmental topographical disorientation: a behavioral and neuroimaging study.

Developmental topographical disorientation (DTD) is the presence of navigational deficits in the context of normal intellectual ability and in the absence of any perinatal, neurological, or psychiatric disorder. As only three cases of DTD have been fully described thus far, we are still unable to draw definitive conclusions about its nature and relationship with other visuospatial competencies, such as mental rotation. The case of Mr. L.A., a 38-year-old man with no history of neurological or psychiatric disorders, sheds some light on these open questions. A neuropsychological assessment including IQ, memory, visuospatial, visuoconstructive, and navigational tests showed that Mr. L.A. has pure navigational deficits affecting both route knowledge and cognitive map processing. Unlike previously described cases of DTD, Mr. L.A. was not affected by any other visuospatial or visuoconstructive deficits. In a functional magnetic resonance imaging (fMRI) task involving the recall of route knowledge, Mr. L.A. showed activation in the occipital areas, involved in low-level perceptual analysis of the stimuli, and showed no activation in the areas activated in controls with regard to route knowledge. The present case suggests that different types of DTD exist, which are characterized by different navigational difficulties and anomalous/lacking functional brain activities in specific navigational networks.

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.

Neglecting the left side of a city square but not the left side of its clock: prevalence and characteristics of representational neglect.

Representational neglect, which is characterized by the failure to report left-sided details of a mental image from memory, can occur after a right hemisphere lesion. In this study, we set out to verify the hypothesis that two distinct forms of representational neglect exist, one involving object representation and the other environmental representation. As representational neglect is considered rare, we also evaluated the prevalence and frequency of its association with perceptual neglect. We submitted a group of 96 unselected, consecutive, chronic, right brain-damaged patients to an extensive neuropsychological evaluation that included two representational neglect tests: the Familiar Square Description Test and the O'Clock Test. Representational neglect, as well as perceptual neglect, was present in about one-third of the sample. Most patients neglected the left side of imagined familiar squares but not the left side of imagined clocks. The present data show that representational neglect is not a rare disorder and also support the hypothesis that two different types of mental representations (i.e. topological and non-topological images) may be selectively damaged in representational neglect.

Landmark sequencing and route knowledge: an fMRI study.

INTRODUCTION: The ability to navigate in a familiar environment mainly relies on route knowledge, that is, a mental representation of relevant locations along a way, sequenced according to a navigational goal. Despite the clear ecological validity of this issue, route navigation and route knowledge have been scarcely investigated and little is known about the neural and cognitive bases of this navigational strategy. Using functional magnetic resonance imaging (fMRI) we tested the validity of the predictions based on the main cognitive models of spatial knowledge acquisition about route-based navigation. METHODS: An order judgment task was used with two conditions (route and activity). Subjects were required to detect potential mismatches between a current sensory input and expectations deriving from route and activity knowledge. RESULTS: A medial occipto-temporal (e.g., lingual gyrus, calcarine cortex, fusiform gyrus, parahippocampal cortex) network was found activated during the route task, whereas a temporo-parietal (temporo-parietal junction) and frontal (e.g., Broca's area) network was related to the activity task. CONCLUSIONS: Functional data are congruent with cognitive models of route-based navigation. The route task activated areas related to both landmark identity and landmark order. Data are discussed in view of route-based navigation models.

Role of visuo-spatial working memory in path integration disorders in neglect.

This paper investigates the relationship between memory deficits and navigational ability in neglect. In recent studies (Piccardi et al., 2008a, 2010; Bianchini et al., 2010), a dissociation was found in visuo-spatial memory for peripersonal/reaching space and visuo-spatial memory for navigational space, suggesting that the latter is processed by a specific system devoted to storing environmental information for navigational purposes (Piccardi et al., 2010). Specific deficits have also been described in neglect patients in navigational tasks requiring to memorize and retrieve a target location in a real environment. In order to analyze the relation between visuo-spatial memory for different type of space (reaching vs navigational) and its relation with navigational processes, in the present study, we compared the performance of right brain-damaged patients with and without neglect on visuo-spatial memory both in peripersonal/reaching (Corsi Block-Tapping test) and in navigational (Walking Corsi test Laser) space with performances on navigational tests (a human version of the Morris Water Maze). Results indicate that a specific deficit in navigational working memory affects navigational ability in neglect patients. Indeed, neglect patients' difficulty in using path integration to navigate in the environment is directly correlated with a deficit in visuo-spatial working memory. These results support the existence of a specific memory system devoted to representing environmental information for navigational purposes and separate from visuo-spatial memory systems, which stores information in peripersonal/reaching space.

Topographical disorientation in a patient who never developed navigational skills: the (re)habilitation treatment.

Although many cases of topographical disorientation are described in the literature, very few attempts have been made to rehabilitate this deficit, most likely because it is a multi-faceted syndrome in which different patients are affected by different topographical deficits. Therefore, it is not easy to develop a single rehabilitation programme to improve all types of topographical disorders. We describe the rehabilitation of a young woman with selective and pervasive topographical disorientation who never developed navigational skills due to a cerebral malformation bilaterally involving the retrorolandic regions. During treatment, the patient was trained to explore her surroundings carefully, to orient herself and then to move in the environment using a language-based strategy. At the end of the treatment, the patient was able to navigate in the environment by adopting several cognitive strategies useful for orientation. This result was maintained at the one-year follow-up, at which time the patient was also able to reach locations she had never been to alone. These results suggest that even patients who have never developed the ability to orient themselves in the environment can still achieve very good functional recovery if they are accurately assessed and submitted to a specific rehabilitation intervention.

Rehabilitation of attention in two patients with traumatic brain injury by means of 'attention process training'.

PRIMARY OBJECTIVE: This case study aims to evaluate the effectiveness of the Solhberg and Mateer's Attention Process Training (APT) using a comprehensive evaluation of various attentional processes. METHODS AND PROCEDURES: Two patients with severe traumatic brain injury were given the APT in a chronic phase. Attentional processes were evaluated at various stages before, during and after treatment, using the Testbatterie zur Aufmerksamkeitsprufung and the Test of everyday attention. MAIN OUTCOMES AND RESULTS: Both patients showed some degree of recovery, particularly in attentional tasks with a selective component. Lesser improvement was present in the case of tasks mapping on the intensity dimension of attention (alertness, vigilance). Training achievements were confirmed by the use of a functional scale evaluating attention, pointing to the generality of improvements. CONCLUSION: The results indicate selective training effects of APT on the attentional disturbances of TBI patients.

Lack of orientation due to a congenital brain malformation: a case study.

Topographical disorientation is usually described in patients who have lost the ability to orient themselves as a consequence of acquired focal brain damage. Here, we describe the case of a 20-year-old woman with a congenital brain malformation who has never been able to orient herself within the environment. We addressed in detail her ability to orient and navigate within the environment by administering a number of tasks in both ecological and experimental surroundings. The results indicate a complete inability to use any kind of strategy useful for orientation.

Reaction and movement times in individuals with chronic traumatic brain injury with good motor recovery.

Reaction times and movement times were studied in 18 individuals with severe traumatic brain injury (TBI) and 36 matched normal controls. Reaction times depended on the type of task: in the case of simple visual stimuli (Alertness condition) they were similar in individuals with TBI and normal controls. In contrast, individuals with TBI were slower in a Go-no-go test. Regardless of task, movement times depended on movement length and were slower in individuals with TBI. These findings indicate the presence of a residual motor programming deficit in individuals with TBI even in the chronic stage and in the presence of good motor recovery, as assessed clinically.

The right hemisphere involvement in the processing of morphologically derived words.

It is widely documented that the left hemisphere is dominant in all complex linguistic tasks, including the processing of inflectional morphology. Both in Italian and in other languages, patients with brain damage with a selective deficit in derivational morphology have never been reported. Here we present the unusual case of two patients with very similar right-hemisphere lesions, who in the absence of aphasic disorders showed a selective inability in producing derivational morphology. Although both patients were unimpaired in producing verb infinitives, they both showed a selective deficit in producing nouns derived from verbs. This difficulty was not present in deriving nouns from other grammatical categories, such as adjectives. Interestingly, both patients mostly substituted the derived noun with the past participle of the verb. This pattern of results documents for the first time a right-hemisphere contribution in the domain of derivational morphology.