Adina R. Lew

Looking beyond the boundaries: Time to put landmarks back on the cognitive map?

Since the proposal of Tolman (1948) that mammals form maplike representations of familiar environments, cognitive map theory has been at the core of debates on the fundamental mechanisms of animal learning and memory. Traditional formulations of cognitive map theory emphasize relations between landmarks and between landmarks and goal locations as the basis of the map. More recently, several models of spatial coding have taken the boundaries of an environment as the basis of the cognitive map, with landmark relations being processed through alternative, operant learning mechanisms. In this review, the evidence for this proposed dichotomy is analyzed. It is suggested that 2 factors repeatedly confound efforts to compare spatial coding based on landmark arrays, formed by 2 or more landmarks, and that based on the boundaries of an environment. The factors are the perceived stability of the landmark arrays and their placement relative to the larger environment. Although the effects of landmark stability and of placement on spatial navigation have been studied extensively, the implications of this work for debates concerning the role of boundaries in cognitive map formation have not been fully realized. It is argued that when these 2 factors are equated between landmark arrays and bounded environments, current evidence supports a commonality of spatial coding mechanism rather than a dichotomy. The analysis places further doubt on the existence of a dedicated geometric module for reorientation and is consistent with models of navigation containing mapping and operant learning components, both taking as input local views (Sheynikhovich et al., 2009).

The development of hand-mouth coordination in 2- to 5-month-old infants : Similarities with reaching and grasping

Abstract Recent studies have found that elements of hand–mouth coordination are embedded within the spontaneous general movements of newborns. Little is known about the subsequent development of the coordination, however. The hand–mouth movements of 14 infants were studied longitudinally between 2–5 months of age at monthly intervals. At 4 months of age, contacts on other parts of the face diminished, such that there was a focus on the mouth. Anticipatory mouth opening was not found at 4 months but started to occur at 5 months. These results are accounted for in terms of involuntary general movements, as well as neuromuscular immaturity constraining the expression of hand–mouth coordination before 4 months of age. This pattern of development compares with the related coordination of reaching and grasping.

Use of cue configuration geometry for spatial orientation in human infants (Homo sapiens).

Research with both rats and human infants has found that after inertial disorientation, the geometry of an enclosed environment is used in preference over distinctive featural information during goal localization. Infants (Homo sapiens, 18-24 months) were presented with a toy search task involving inertial disorientation in 1 of 2 conditions. In the identical condition, 4 identical hiding boxes in a rectangular formation were set within a circular enclosure. In the distinctive condition, 4 distinctive hiding boxes were used. Infants searched the goal box and its rotational equivalent significantly more than would be expected by chance in the identical condition, showing that they were sensitive to the geometric configuration of the array of boxes. Unlike the results of studies using a rectangular enclosure, however, in the distinctive condition, infants searched at the correct location significantly more than at other locations.

The effects of hunger on hand-mouth coordination in newborn infants

The spontaneous hand–mouth (HM) behavior of a group of newborn infants was analyzed before and after feeding to examine the hypothesis that there is a link between hunger and HM coordination. There was no difference in the relative distribution of contacts on the mouth compared with other parts of the face as a result of feeding. However, significantly more mouth opening before contacts to the mouth than those to the face occurred before but not after feeding. It was suggested that HM coordination was linked to feeding, but because of involuntary general movements infants might not be able to determine the final location of a movement. However, they are able to predict where a movement will land and anticipate this, if motivated to do so.

The Impact of Community Rehabilitation for Acquired Brain Injury on Carer Burden: An Exploratory Study

ObjectivesThis study evaluated the relative efficacy of a community rehabilitation service and a more traditional outpatient service for carers of people with an acquired brain injury. MethodsSeventeen carers who had received a community intervention were retrospectively compared with 24 carers who had received an outpatient service. Dependent variables were level of met family need, a measure of family dysfunction, carer psychopathology, and carer emotional acceptance. ResultsThe community sample fared significantly better on all measures except carer psychopathology. ConclusionsThese results suggest that community-based services have efficacy for the carer and family. There is a clear need for large clinical trials using standardized instruments to establish what models of service delivery benefit carers.

Social cognition in children with epilepsy in mainstream education

To establish whether deficits in social cognition are present in children with generalized or focal epilepsy in mainstream education, and whether any relation exists between social cognition, communication, and behaviour measures.

The development of beacon use for spatial orientation in 6-8.5-month-old infants

The overall aim of this research was to establish the youngest age at which use of beacons to aid spatial orientation could be demonstrated. Six- and 8.5-month-old infants were tested in a peekaboo paradigm in which they had to turn to a target location, either after displacement to a novel position and orientation (Study 1), or to a novel orientation only (Study 2). A beacon condition where there was a colourful landmark at the peekaboo location was contrasted with a non-beacon condition at each age. The 8.5-month-olds showed robust but modest gains in performance in the presence of a beacon, whereas the 6-month-old infants did not. A further study (Study 3) confirmed that performance was poor at 8.5 months in the absence of a beacon, even when displacements between training and test positions involved rotations only. This finding is contrary to that reported in earlier literature (Tyler and McKenzie, 1990). The possibility that onset of crawling (at a mean age of 8.5 months) could be linked both to the development of allocentric and egocentric spatial coding is left open by the relatively later age of competence found in the present series of studies.

Transfer of spatial search between environments in human adults and young children (Homo sapiens): Implications for representation of local geometry by spatial systems

Whether animals represent environmental geometry in a global and/or local way has been the subject of recent debate. We applied a transfer of search paradigm between rectangular- and kite-shaped arenas to examine the performance of human adults (using virtual environments) and children of 2.5-3.5 years (using real arenas). Adults showed robust transfer to a congruent corner in a kite-shaped arena, following training in a rectangular-shaped arena in two paradigms modeled on those used with rats and young children respectively. In contrast, the children showed no evidence of transfer of search, despite above chance performance in the rectangular arena, and above chance performance in a study where search occurred in the kite arena only. The pattern of findings suggests global aspects of environmental geometry may be used to re-establish heading, and that the matching of elements of local geometry in new global contexts may be an advanced developmental achievement.

‘Psychosocial problems and seizure‐related factors in children with epilepsy’

with epilepsy’ SIR – We read with interest the article by Hoie et al.1 and note that the highest level of problems were found in the symptomatic and probable symptomatic group. We would like to suggest that one contributory cause to these psychosocial problems may be problems of social understanding, i.e. lack of understanding of the thoughts and intentions of others in interpersonal interactions. Problems of communication and social understanding in children with refractory focal epilepsy have been well documented.2,3 However, samples including children with well-controlled seizures and a probable symptomatic (cryptogenic) diagnosis have received less research attention. We invited 104 parents of children between the ages of 4 and 16 years within the caseload of the epilepsy nurse at the Royal Preston Hospital, Preston, UK, to complete the Children’s Communication Checklist, 2nd edition (CCC-II).4 These cases were selected such that the child was in mainstream education and the diagnosis was either idiopathic or probable symptomatic epilepsy. The CCC-II is a validated and standardized instrument for screening for clinically relevant communication problems, including specific language impairment and autistic spectrum disorder. Thirty-three questionnaires were returned, although only 31 could be used due to missing responses. The cases were categorized as focal (n=16; seven females, nine males), generalized (n=12; seven females, five males), or undetermined (n=3; two females, one male) based on information in the medical file of each child. Clinical presentation and electroencephalogram recordings formed the basis of diagnosis, with magentic resonance imaging data available for most of the sample. There was no significant difference between focal and generalized groups in terms of chronological age, but there was a trend for the focal group to have an earlier age at onset than the generalized group (focal: mean age 4y 6m [SD 2y 6m]; generalized: mean age 6y 9m [SD 3y]; t(26)=1.9, p=0.07), so age at onset was entered as a covariate when comparing the two groups on questionnaire data. Seventy-five per cent of the focal group was on monotherapy, with 69% of the group achieving seizure control. Fifty-eight per cent of the generalized group was on monotherapy and 75% of the group had achieved seizure control. The focal group scored significantly lower than non-clinical norms on all 10 subscales of the CCC-II (ranging from measures of syntax to social interaction and interests). They also scored significantly lower than non-clinical norms (scaled normed score=82) on a summary measure, the General Communication Composite (GCC; mean 48.5 [SD 29.0]; t=4.6, p<0.001). None of the differences between the generalized epilepsy group and non-clinical norms was significant, although the generalized group was heterogeneous, containing some children that scored very poorly, and others who showed superior performance. There were significant differences between the generalized and focal group for speech (F[1,25]=6.1, η2=0.20, p<0.05), syntax (F[1,25]= 5.5, η2=0.18, p<0.05), and stereotyped use of language (F[1, 25]=4.5, η2=0.15, p<0.05). GCC scores were also significantly higher for the generalized group relative to the focal group (F[1, 25]=4.3, η2=0.15, p<0.05). There was no other significant difference (possibly due to limited power), and age of onset was not significant as a factor in any comparison. Although there was clearly self-selection in the sample, this cannot fully account for the poor performance of the focal group, as the generalized group did not show this poor profile. Despite the preliminary nature of these data, it does suggest that clinicians and educators need to be aware that children with focal epilepsies may be particularly vulnerable to problems of social understanding and communication, irrespective of whether there is seizure control.

Reading comprehension difficulties in children with rolandic epilepsy

Difficulties in reading comprehension can arise from either word reading or listening comprehension difficulties, or a combination of the two. We sought to determine whether children with rolandic epilepsy had poor reading comprehension relative to typically developing comparison children, and whether such difficulties were associated with word reading and/or general language comprehension difficulties.