|
| Investigator | Subject groups | Average age | Paradigm | Tested brain function | Method of analysis | Main findings in patients compared with ctls | Conclusion |
|
Arce et al.
2006 [46] | 17 csz
17 ctrls | 41
40 | Visual Go/Nogo task with matched performance accuracy between csz and ctrls | Inhibition and cue processing | fMRI | During cued inhibition: greater activation in the left precuneus and left superior temporal gyrus
During inhibition: less ACC and DLPFC activation
Implicit cue trials: greater inferior frontal gyrus activation | Csz have difficulties with inhibition and clue processing |
|
Braus et al.
2006 [47] | 11 FE
11 ctrls | 25
29 | Simultaneous presentation of acoustical and optical inputs | Basic sensory input circuits | fMRI | Less activation of the PL, right thalamus, the right prefrontal cortex | Already at disease onset deficits in information processing are existing |
|
Broome et al.
2009 [48] | 17 UHR
10 FEP
15 ctrls | 24
26
25 | Verbal fluency task and an N-back | WM | fMRI | Activation pattern in UHR was during the N-back task different in dorsolateral prefrontal and parietal cortex compared to ctrls | The level of regional activation in the UHR group was intermediate between that in the FE group and ctrls |
|
Franck et al.
2002 [49] | 87 csz | 31 | Instructed to relax and not perform any tasks | Random episodic silent thought (REST) | PET | Schneiderian score positively correlated with rCBF in right superior parietal cortex and negatively correlated with rCBF in left posterior cingulate gyrus and in left lingual gyrus | Findings support hypothesis that cerebral pattern of activation is linked to symptoms of SZ |
|
Henseler et al.
2010 [50] | 12 csz
12 ctrls | 33
32 | Verbal item-recognition task and a visuospatial item-recognition task | WM | fMRI | SZ showed reduced connectivity of the prefrontal cortex with the intraparietal cortex and the hippocampus | Altered prefronto-hippocampal and parieto-occipital connectivity was found to be associated with higher positive symptoms |
|
Hugdahl et al.
2004 [51] | csz
depressed pts
ctrls | 32
33
31 | First task: pressing a response button whenever a specific number was seen
Second task: adding two consecutive numbers | Vigilance task
Mental arithmetic task | fMRI | Less activation in prefrontal brain regions and greater parietal lobe activation relative compared to ctrls and patients with major depression. | In support double dissociation of parietal and frontal lobe activation between SZ and depression |
|
Keedy et al.
2006 [52] | 15 FE
24 ctrls | 25
25 | Eye movement tasks: visually guided saccade, smooth pursuit paradigms and oculomotor delayed response paradigm | Oculomotor function
Spatial working memory | fMRI | Reduced activation in sensorimotor areas supporting eye movement control: parietal cortex, frontal eye fields, supplementary eye fields, and cingulated cortex | Generalized pattern of cortical dysfunction already present early SZ |
|
Keshavan et al.
2002 [53] | 4 GHR
4 ctrls | 13
13 | Memory-guided saccade task | Spatial working memory | fMRI | Decreased activation in the inferior parietal cortex and the DLPFC | Dysfunction of prefrontal and parietal regions in GHR |
|
Kim et al.
2003 [54] | 12 csz
12 ctrls | 26
26 | n-back sequential picture task | WM | PET | Dorsolateral prefrontal, ventrolateral prefrontal and bilateral inferior parietal region activation abnormalities | Indicating that during working memory tasks there could be a parietofrontal disconnection |
|
Öngür et al.
2006 [55] | 20 csz
17 ctrls | 40
38 | Discrimination of previously seen and new pairs of visual stimuli | Relational memory | fMRI | While discriminating novel pairs decreased activation of the right parietal cortex and the anterior cingulate cortex | Deficit of relational memory connected to dysfunctional activation of the parietal cortex and the hippocampus |
|
Ojeda et al.
2002 [56] | 11 csz drug naive
10 ctrls | 28
26 | Auditory stimulation task
Counting tasks with or without auditory stimulation | Attention tasks | PET | Inadequate activation of parietal and frontal regions during performance of cognitively emanding tasks | Evidence of compensatory mechanisms in frontoparietal regions |
|
Paulus et al.
2003 [57] | 15 scz
15 ctrls | 42
41 | Two-choice prediction task | Decision making with different degrees of uncertainty | fMRI | PL less activated in decision making in situations with high uncertain outcome | Inadequate processing in situations of uncertainty in the posterior parietal cortex |
|
Quintana et al.
2003 [58] | 8 sz
8 ctrls | | Anticipatory task
Retention task | WM | fMRI | Anticipatory task: decreased PFC and increased PPC activation
Retention task: increased PFC activation | PFC shows more hypoactivation than PPC is able to compensate |
|
Sanz et al.
2009 [59] | 13 csz
no information about ctrls included | 20 | verbal capacity task | verbal WM | fMRI | Lower levels of activation in frontal lobe, PL in the left hemisphere | Dysfunctional activation during WM processing related to the severity of negative and disorganized symptoms |
|
Schneider et al.
2007 [60] | 48 FE
57 ctrls | 31
31 | 2- and 0-back tasks | WM
attention connected processes | fMRI | Working memory: parietal hypoactivations, combined with hyperfrontality in VLPFC
Attention-connected processes: hypoactivations in the VLPFC, superior temporal cortex, thalamus | Dysfunctional cerebral network not able to cope with required activation for attention and WM tasks |
|
Sweeney et al.
2003 [61] | 8 csz with auditory hallucinations
8 ctrls | 31
29 | Fast versus slow covert articulation of a word at two self-paced rates | Processing inner speech | fMRI | Reduced activation in the right superior temporal, inferior parietal, and parahippocampal regions | SZ patients with auditory hallucinations have aberrant activation pattern of brain regions |
|
Spence et al.
1997 [1] | 7 d-scz
6 nd-scz
6 ctrls | Not stated | Performing movement task
Second PET 4–6 weeks after first PET | Movement | PET | Increased right parietal and cingulate activation in csz with delusions of control but in d-scz with decreased passivity delusion in second scan hyperactivation of right parietal and cingulate remitted | Certain brain regions involved in generating delusions of passivity |
|
Thermenos et al.
2005 [62] | 14 SZ
22 ctrls | 38
38 | Visual letter 2-back task | WM | fMRI | Greater activation in the right medial frontal gyrus and left inferior parietal lobule/medial temporal gyrus region | Heteromodal association cortices show higher activation in SZ during performance of WoM task |
|
Whalley et al.
2006 [63] | 4 GHP-S
26 GHR-P
27 GHR-N
21 ctrls | 23
26
27
27 | Hayling sentence completion test | Word retrieval | fMRI and ROI | GHR-N showed increased activation of the PL and the anterior cingulate | PL and the lingual gyrus could be used to discriminate between converts and nonconverts |
|
Whalley et al.
2004 [64] | 21 GHR-P
48 GHR-N
21 ctrls | 25
27
27 | Part of Hayling sentence completion test | Verbal initiation | fMRI | GHR-P: increased activation in the left inferior parietal lobule
GHR-N: less activity in medial prefrontal, thalamic and cerebellar regions | Soonest changes in patients with symptoms may be connected to hyperactivation in the parietal lobe |
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