**7. Current research**

In light of the methodological problems highlighted in previous studies, the author and colleagues (McCagh et al., unpublished) designed a study to explore socio-cognitive functioning in people with seizure foci in the RF, LF, RT, LT lobes. To overcome previous sample size difficulties the minimum number of people within each group was 11. As well as a healthy control group, this study recruited an IGE and FHI (frontal head injured) group to establish the impact that focal epilepsy and in particular FLE have on these skills, as Farrant et al. (2005) argue, social cognition has not been fully explored in FLE. Information was also collected on relevant epilepsy related variables (age at onset, AEDs, seizure frequency and duration of epilepsy) in relation to the sample. The study also aimed to establish the impact that socio-cognitive functioning may have on the every day life of PWE by assessing social cognitive performance in relation to perceived impact of epilepsy using the Impact of Epilepsy Scale (Jacoby et al., 1993).

Appreciation of false belief and deception in ToM stories and understanding veiled intentions in the Hinting Task were assessed across all clinical groups. All epilepsy groups were administered the Impact of Epilepsy Scale to compare task performance in relation to the perceived impact of epilepsy, this could then help to establish how socio-cognitive skills are related to social functioning in real life.

To date this is the largest lesion study to investigate ToM and the largest study within the field of epilepsy to investigate social cognition. The findings of this research are currently being

Social Cognition in Epilepsy 277

Goel et al., 1995; Saxe & Kanwisher, 2003; Vogeley et al., 2001), both lobes would appear to be implicated in the processing of ToM. Therefore future research should incorporate

Often it has been too difficult to compare the findings of studies which employ different ToM paradigms. Harrington et al. (2005) reviewed 30 studies testing ToM in schizophrenia and concluded that ToM deficits are apparent but that comparison of results was difficult due to the fact that a variety of ToM measures were used to test the same construct e.g. irony and picture board stories, deception, false belief, hinting etc. As Baron-Cohen et al. (1995) suggest, ToM may be underpinned by a network of many neural structures which could represent different aspects of ToM abilities and differing task demands. Consequently this may account for the disparity in research findings. Therefore future research should endeavour to administer ToM test batteries that assess ToM using techniques that are validated and incorporate measures of general inferential ability, executive function and memory. This will help to establish if ToM abilities are domain general or domain specific skills. Immediate story recall mediated some of the ToM deficits observed in the authors research and so should be accounted for when assessing ToM in future studies. To enable more fruitful comparison between research findings, future research needs to use similar ToM tasks across different populations or to carefully monitor variations in task demand

Studies should further explore the effects of brain damage at different stages of development to ToM (Happé et al., 1999). This would differentiate the importance of specific structures in the development of ToM and in online ToM abilities in adulthood. Whilst some studies have attempted to do this (Shaw et al., 2004) there is lack of research in this area. Inconsistent findings across studies using adult samples may in part be due to the difficulty in finding appropriate measures to assess ToM in adult populations. Tests need to be hard enough to 'generate errors yet simple enough that errors are not merely due to more general processing demands' (Apperley et al., 2004, p.1774.). Future work could endeavour to develop more sophisticated measures. Studies should utilise more ecological valid measures of testing which reflect the complex subtle social cues that are apparent in human social interaction (Lough et al., 2006). To date most research which has investigated sociocognitive functioning specifically in relation to ToM has used vignettes depicting social interactions or photographs illustrating different emotional expressions. Traditional measures are easy to administer but may not necessarily tap into the complex perceptual processes that occur when we interpret social interactions. Future work should use ecologically valid measures of dynamic social interaction as it occurs in everyday life. It has been asserted that the TASITS is a much more ecologically valid measure of emotion recognition and social inference than traditional measures. This test might be incorporated into future research as it may be particularly sensitive in detecting impairments in social functioning. It has been used in one epilepsy study to date (Schilbach et al., 2007) and has been shown to be a valid measure of social cognition in people with head injury in past

One of the main problems in investigating social cognition in epilepsy is that it is difficult to differentiate between the impact of development, the epileptic foci, AED therapy and surgery on the social abilities of PWE (Kirsch 2006). A number of studies have shown that quality of life scores increase after surgery but often these measures do not adequately assess improvements in social functioning (Kirsch, 2006). As Schilbach et al. (2007) argue, social competence has a considerable effect on quality of life yet the study of social cognition

patients with unilateral lesions to both the frontal and temporal lobes.

with corresponding active brain regions.

research (McDonald et al., 2003).

written up for publication. A major outcome from the study is that the RF epilepsy group consistently under performed on ToM tasks. They illustrated deficits across two different ToM paradigms, appreciation of first and second order false belief and deception and appreciation of non-literal language in the Hinting Task in relation to the other experimental groups. These findings indicate that impaired ToM may be a particular feature of right frontal lobe pathology. The extent of the RF mentalising deficit is evident in their performance on one of the most basic assessment measures of ToM, first order ToM (Stone, 2000).

This deficit in first order ToM cannot be attributed to the impact of immediate story recall or level of education, nor is it a consequence of group differences in IQ, number of AEDs, age of onset or duration of epilepsy. The RF group also appear to have difficulty in making inferences based on non-literal language. They were significantly worse on this task than all of the other experimental groups, though further analyses revealed that this deficit was mediated by immediate story recall. The LT were impaired on second order ToM tasks and appreciation of hints though both of these deficits were mediated by immediate story recall. NC performed significantly better on the Hinting Task than all of the patient groups.

The results did not show a significant difference between the epilepsy groups on the Impact of Epilepsy score. Only a subgroup of participants were included in this analysis as this questionnaire was administered part way through recruitment. Therefore this sub sample may not have been representative of the entire target population, though there is no specific evidence to suggest this was the case. The RF group did rate the impact of epilepsy higher than any of the other groups but given the small cell sizes, there may not have been sufficient power to detect significant differences between the groups and so it is necessary to exercise caution in interpreting these findings. PWE do not appear to have insight into their social functioning difficulties, which may well reflect underlying pathology. Interestingly there was a significant negative correlation between impact of epilepsy score and level of education suggesting that the more educated the individual was the more likely they were to realise the social restraints of their condition.

The exact site of lesion within the frontal and temporal lobes is not analysed in relation to task performance. Whilst seizure foci and lateralisation are clearly established, there was no more detailed information available for the PWE included in this study to further localise the exact anatomical site of the seizure focus. Thus the information obtained for this study was not detailed enough to make generalisations about how important specific anatomical locations were within the frontal and temporal lobes in the processing of the tasks used.

#### **8. Directions for future research**

Small sample sizes have reduced the statistical power of findings in many of the studies discussed in the literature review (Farrant et al., 2005; Schilbach et al., 2007; Shaw et al., 2007; Walpole et al., 2008), clearly there is a need for studies with larger sample sizes that will enable comparisons across anatomical lesion sites in the frontal and temporal lobes. None of the epilepsy studies that were reviewed recruited a suitable control group or assessed both right and left frontal and temporal groups. The authors current research, recruited an IGE group, who were also taking AEDs to reduce the possibility that the impact of medication might confound the results. Future study designs need to consider these issues. Lesion studies have to date mostly focused on assessing ToM in either patients with frontal or temporal lobe damage but as this study (McCagh et al., unpublished) and brain imaging studies have shown (Brunet et al., 2000; Fletcher et al.,1995; Gallagher et al., 2000;

written up for publication. A major outcome from the study is that the RF epilepsy group consistently under performed on ToM tasks. They illustrated deficits across two different ToM paradigms, appreciation of first and second order false belief and deception and appreciation of non-literal language in the Hinting Task in relation to the other experimental groups. These findings indicate that impaired ToM may be a particular feature of right frontal lobe pathology. The extent of the RF mentalising deficit is evident in their performance on one of

This deficit in first order ToM cannot be attributed to the impact of immediate story recall or level of education, nor is it a consequence of group differences in IQ, number of AEDs, age of onset or duration of epilepsy. The RF group also appear to have difficulty in making inferences based on non-literal language. They were significantly worse on this task than all of the other experimental groups, though further analyses revealed that this deficit was mediated by immediate story recall. The LT were impaired on second order ToM tasks and appreciation of hints though both of these deficits were mediated by immediate story recall.

NC performed significantly better on the Hinting Task than all of the patient groups.

The results did not show a significant difference between the epilepsy groups on the Impact of Epilepsy score. Only a subgroup of participants were included in this analysis as this questionnaire was administered part way through recruitment. Therefore this sub sample may not have been representative of the entire target population, though there is no specific evidence to suggest this was the case. The RF group did rate the impact of epilepsy higher than any of the other groups but given the small cell sizes, there may not have been sufficient power to detect significant differences between the groups and so it is necessary to exercise caution in interpreting these findings. PWE do not appear to have insight into their social functioning difficulties, which may well reflect underlying pathology. Interestingly there was a significant negative correlation between impact of epilepsy score and level of education suggesting that the more educated the individual was the more likely they were

The exact site of lesion within the frontal and temporal lobes is not analysed in relation to task performance. Whilst seizure foci and lateralisation are clearly established, there was no more detailed information available for the PWE included in this study to further localise the exact anatomical site of the seizure focus. Thus the information obtained for this study was not detailed enough to make generalisations about how important specific anatomical locations were within the frontal and temporal lobes in the processing of the tasks used.

Small sample sizes have reduced the statistical power of findings in many of the studies discussed in the literature review (Farrant et al., 2005; Schilbach et al., 2007; Shaw et al., 2007; Walpole et al., 2008), clearly there is a need for studies with larger sample sizes that will enable comparisons across anatomical lesion sites in the frontal and temporal lobes. None of the epilepsy studies that were reviewed recruited a suitable control group or assessed both right and left frontal and temporal groups. The authors current research, recruited an IGE group, who were also taking AEDs to reduce the possibility that the impact of medication might confound the results. Future study designs need to consider these issues. Lesion studies have to date mostly focused on assessing ToM in either patients with frontal or temporal lobe damage but as this study (McCagh et al., unpublished) and brain imaging studies have shown (Brunet et al., 2000; Fletcher et al.,1995; Gallagher et al., 2000;

the most basic assessment measures of ToM, first order ToM (Stone, 2000).

to realise the social restraints of their condition.

**8. Directions for future research** 

Goel et al., 1995; Saxe & Kanwisher, 2003; Vogeley et al., 2001), both lobes would appear to be implicated in the processing of ToM. Therefore future research should incorporate patients with unilateral lesions to both the frontal and temporal lobes.

Often it has been too difficult to compare the findings of studies which employ different ToM paradigms. Harrington et al. (2005) reviewed 30 studies testing ToM in schizophrenia and concluded that ToM deficits are apparent but that comparison of results was difficult due to the fact that a variety of ToM measures were used to test the same construct e.g. irony and picture board stories, deception, false belief, hinting etc. As Baron-Cohen et al. (1995) suggest, ToM may be underpinned by a network of many neural structures which could represent different aspects of ToM abilities and differing task demands. Consequently this may account for the disparity in research findings. Therefore future research should endeavour to administer ToM test batteries that assess ToM using techniques that are validated and incorporate measures of general inferential ability, executive function and memory. This will help to establish if ToM abilities are domain general or domain specific skills. Immediate story recall mediated some of the ToM deficits observed in the authors research and so should be accounted for when assessing ToM in future studies. To enable more fruitful comparison between research findings, future research needs to use similar ToM tasks across different populations or to carefully monitor variations in task demand with corresponding active brain regions.

Studies should further explore the effects of brain damage at different stages of development to ToM (Happé et al., 1999). This would differentiate the importance of specific structures in the development of ToM and in online ToM abilities in adulthood. Whilst some studies have attempted to do this (Shaw et al., 2004) there is lack of research in this area.

Inconsistent findings across studies using adult samples may in part be due to the difficulty in finding appropriate measures to assess ToM in adult populations. Tests need to be hard enough to 'generate errors yet simple enough that errors are not merely due to more general processing demands' (Apperley et al., 2004, p.1774.). Future work could endeavour to develop more sophisticated measures. Studies should utilise more ecological valid measures of testing which reflect the complex subtle social cues that are apparent in human social interaction (Lough et al., 2006). To date most research which has investigated sociocognitive functioning specifically in relation to ToM has used vignettes depicting social interactions or photographs illustrating different emotional expressions. Traditional measures are easy to administer but may not necessarily tap into the complex perceptual processes that occur when we interpret social interactions. Future work should use ecologically valid measures of dynamic social interaction as it occurs in everyday life. It has been asserted that the TASITS is a much more ecologically valid measure of emotion recognition and social inference than traditional measures. This test might be incorporated into future research as it may be particularly sensitive in detecting impairments in social functioning. It has been used in one epilepsy study to date (Schilbach et al., 2007) and has been shown to be a valid measure of social cognition in people with head injury in past research (McDonald et al., 2003).

One of the main problems in investigating social cognition in epilepsy is that it is difficult to differentiate between the impact of development, the epileptic foci, AED therapy and surgery on the social abilities of PWE (Kirsch 2006). A number of studies have shown that quality of life scores increase after surgery but often these measures do not adequately assess improvements in social functioning (Kirsch, 2006). As Schilbach et al. (2007) argue, social competence has a considerable effect on quality of life yet the study of social cognition

Social Cognition in Epilepsy 279

likely to be more sensitive to socio cognitive impairment in real life, should be incorporated with more traditional measures to accurately establish the impairments of social perception in PWE. Such assessments should be complemented by an effective measure of the actual social difficulties that PWE experience in everyday life. A number of authors criticise current measures of social functioning used on PWE, currently these measures do not fully explore the impact that surgery has on interpersonal relationships or social competence (Kirsch, 2006; Schilbach et al., 2007). Therefore development of more appropriate measures

The authors' current research lateralises socio-cognitive dysfunction to the right frontal lobe and left temporal lobe, further study in this area may be able to support the lateralisation of these skills. If this is the case then socio-cognitive assessment may provide clinicians with a useful and inexpensive tool for lateralising the site of seizure foci in patients, particularly where anterior foci are suspected. This may be particularly valuable as there are few neuropsychological tests which can lateralise damage in the prefrontal cortex. The effects of lateralisation or localisation have not been found in studies which assess cognitive functioning in FLE (Helmstaedter et al., 1996; Upton & Thompson, 1996). Tests of social cognition may provide the clinician with an objective measure of deficits in social competence particularly as patients with FLE may lack insight into their impairments. Patients who are at risk of reduced social competence can be identified and may possibly benefit from treatment intervention. Future investigations should assess the efficacy of such

Social cognition is an important but neglected area of study in the field of epilepsy. The study of ToM in epilepsy will lead to a greater understanding of the social cognitive deficits of the epileptic condition. This may in turn lead to more effective psychological

Apperly, I. A., Samson, D., Chiavarino, C., & Humphreys, G. W. (2004). Frontal and

Astington, J.W. (2001). The future of theory-of-mind research: understanding motivational

Austin, K., Smith, M.S., Risinger, M.W., & McNelis, A.M. (1994). Childhood epilepsy and

Austin, K. and deBoer, H. (1997). Disruptions in social functioning and services facilitating

*Comprehensive Textbook* (pp. 2191–2201). Philadelphia: Lippincott-Raven. Avis, J.and Harris, P. (1991). Belief-desire reasoning among Baka children: evidence for a

Bar-On, R. (1997). *The emotional quotient inventory (EQ-I): a test of emotional intelligence*. Multi-

Bar-On, R., Tranel, D., Denburg, N., & Bechara, A. (2003). Exploring the neurological

substrate of emotional and social intelligence. *Brain, 126,* 1790–800.

asthma: comparison of quality of life. *Epilepsia, 35* (3), 608-615.

universal conception of mind. *Child Development, 62*, 460-467.

temporo-parietal lobe contributions to theory of mind: Neuropsychological evidence from a false-belief task with reduced language and executive demands.

states, the role of language, and real-world consequences. *Child Development, 72* (3),

adjustment for the child and adult. In: Engel Jr. J., Pedley, T.A. (Eds.). *Epilepsy: A* 

interventions to enable the smoother functioning of people with epilepsy in society.

*Journal of Cognitive Neuroscience, 16,* 1773-1784.

Health Systems, Toronto, Canada.

is needed.

interventions in epilepsy.

**10. References** 

685-7.

in epilepsy has been largely neglected. Future research needs to continue to explore the impact that socio-cognitive dysfunction has on social functioning and quality of life in FLE and TLE. This could be achieved by administering a wide range of measures that utilise different paradigms in social cognition. Future work should include objective ratings of social functioning to see if real life behaviour is related to socio cognitive task performance. Quality of life measures that fully explore the impact of epilepsy on social functioning that are not self report measures but objective measures completed by significant others need to be employed. This may help resolve the difficulty of insight that appears to be apparent in FLE.

Future research which assesses social cognition before and after surgery is needed (Fournier et al., 2008). Surgery may help reduce seizures activity and reduce the amount of AEDs taken which in turn may improve social cognitive performance. Shaw et al. (2007) found improvements in social cognition (facial expression recognition) in people with left TLE after surgery. There is need for longitudinal research which establishes the impact of surgery on social cognition to establish whether epilepsy surgery is beneficial in improving such skills.

Further research should focus on trying to rehabilitate PWE after surgery where they may find themselves in new social situations that they have not previously experienced and may have difficulty adjusting (Bladin, 1992; Wilson, Bladin & Saling, 2004). PWE may have new found independence which can impact on interpersonal relationships, causing friction and resentment. This may be particularly problematic if parental over protectiveness was a feature before surgery.
