his.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Kallio, Sakari
Publications (10 of 19) Show all publications
Gerafi, J., Samuelsson, H., Viken, J. I., Blomgren, C., Claesson, L., Kallio, S., . . . Jood, K. (2017). Neglect and aphasia in the acute phase as predictors of functional outcome 7 years after ischemic stroke. European Journal of Neurology, 24(11), 1407-1415
Open this publication in new window or tab >>Neglect and aphasia in the acute phase as predictors of functional outcome 7 years after ischemic stroke
Show others...
2017 (English)In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 24, no 11, p. 1407-1415Article in journal (Refereed) Published
Abstract [en]

Background and purpose: Visuospatial inattention (VSI) and languageimpairment (LI) are often present early after stroke and associations with an unfavorable short-term functional outcome have been reported. The purpose of this study was to investigate whether a screening of VSI and LI as indicators of cortical symptoms early after stroke could predict long-term functional outcomes. Methods: A consecutive cohort of 375 patients with ischemic stroke was assessed for the occurrence of VSI at a median of 7 days after admission (interquartile range, 1–5 days) using the Star Cancellation Test and for LI (within the first 7 days) with the language item in the Scandinavian StrokeScale. Seven years later, functional outcomes were assessed by the modified Rankin scale and Frenchay Activities Index in 235 survivors without recurrent stroke. Relationships between baseline predictors and functional outcome at 7 years were analyzed with bivariate correlations and multiple categorical regressions with optimal scaling. Results: The regression model significantly explained variance in the modified Rankin scale (R2= 0.435, P < 0.001) and identified VSI (P=0.001) and neurological deficits (P < 0.001; Scandinavian Stroke Scale score without the language item) as the significant independent predictors. The model for FrenchayActivities Index was also significant (R2= 0.269, P < 0.001) with VSI(P = 0.035) and neurological deficits (P < 0.001) as significant independent predictors. Conclusions: Visuospatial inattention at acute stroke has an independent impact on long-term functional outcomes. Early recognition may enable targeted rehabilitative interventions.

Place, publisher, year, edition, pages
Wiley-Blackwell Publishing Inc., 2017
Keywords
Neglect, aphasia, stroke
National Category
Neurosciences
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-14110 (URN)10.1111/ene.13406 (DOI)000412673700017 ()28803458 (PubMedID)2-s2.0-85029357397 (Scopus ID)
Available from: 2017-09-13 Created: 2017-09-13 Last updated: 2018-01-13Bibliographically approved
Kallio, S., Koivisto, M. & Kaakinen, J. K. (2017). Synaesthesia-type associations and perceptual changes induced by hypnotic suggestion. Scientific Reports, 7, Article ID 17310.
Open this publication in new window or tab >>Synaesthesia-type associations and perceptual changes induced by hypnotic suggestion
2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 17310Article in journal (Refereed) Published
Abstract [en]

Are synaesthetic experiences congenital and so hard-wired, or can a functional analogue be created? We induced an equivalent of form-colour synaesthesia using hypnotic suggestions in which symbols in an array (circles, crosses, squares) were suggested always to have a certain colour. In a Stroop type-naming task, three of the four highly hypnotizable participants showed a strong synaesthesia-type association between symbol and colour. This was verified both by their subjective reports and objective eye-movement behaviour. Two resembled a projector-and one an associator-type synaesthete. Participant interviews revealed that subjective experiences differed somewhat from typical (congenital) synaesthesia. Control participants who mimicked the task using cognitive strategies showed a very different response pattern. Overall, the results show that the targeted, preconsciously triggered associations and perceptual changes seen in association with congenital synaesthesia can rapidly be induced by hypnosis. They suggest that each participant's subjective experience of the task should be carefully evaluated, especially when studying hypnotic hallucinations. Studying such experiences can increase understanding of perception, automaticity, and awareness and open unique opportunities in cognitive neuroscience and consciousness research.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
Keywords
Hypnosis, Synaesthesia, attention, Color perception, Automaticity
National Category
Behavioral Sciences Biology Neurosciences
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-14606 (URN)10.1038/s41598-017-16174-y (DOI)000417570500029 ()29229939 (PubMedID)
Available from: 2017-12-28 Created: 2017-12-28 Last updated: 2018-02-16Bibliographically approved
Kallio, S. & Koivisto, M. (2016). Seeing Blue As Red: A Hypnotic Suggestion Can Alter Visual Awareness of Colors. International journal of clinical and experimental hypnosis, 64(3), 261-284
Open this publication in new window or tab >>Seeing Blue As Red: A Hypnotic Suggestion Can Alter Visual Awareness of Colors
2016 (English)In: International journal of clinical and experimental hypnosis, ISSN 0020-7144, E-ISSN 1744-5183, Vol. 64, no 3, p. 261-284Article in journal (Refereed) Published
Abstract [en]

Some highly hypnotizable individuals have reported changes in objects' color with suggestions given in normal waking state. However, it is not clear whether this occurs only in their imagination. The authors show that, although subjects could imagine colors, a posthypnotic suggestion was necessary for seeing altered colors, even for a hypnotic virtuoso. She reported posthypnotic color alterations also selectively in response to specific target shapes in briefly presented object arrays. Surprisingly, another highly hypnotizable person showed a very different pattern of results. The control participants could not simulate virtuosos' results by applying cognitive strategies. The results imply that hypnosis can alter the functioning of automatic visual processes but only in some of the most hypnotizable individuals.

Place, publisher, year, edition, pages
Taylor & Francis, 2016
Keywords
Color perception, hypnosis, hallucination
National Category
Other Biological Topics Other Biological Topics
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-12744 (URN)10.1080/00207144.2016.1171088 (DOI)000378742800001 ()27267673 (PubMedID)2-s2.0-84975463604 (Scopus ID)
Available from: 2016-08-08 Created: 2016-08-08 Last updated: 2017-11-28Bibliographically approved
Virta, M., Hiltunen, S., Mattsson, M. & Kallio, S. (2015). The impact of hypnotic suggestions on reaction times in continuous performance test in adults with ADHD and healthy controls. PLoS ONE, 10(5), Article ID e0126497.
Open this publication in new window or tab >>The impact of hypnotic suggestions on reaction times in continuous performance test in adults with ADHD and healthy controls
2015 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 5, article id e0126497Article in journal (Refereed) Published
Abstract [en]

Attention is one of the key factors in both hypnotic processes and patients with ADHD. In addition, the brain areas associated with hypnosis and ADHD overlap in many respects. However, the use of hypnosis in ADHD patients has still received only minor attention in research. The main purpose of the present work was to investigate whether hypnosis and hypnotic suggestions influence the performance of adult ADHD (n = 27) and control participants (n = 31) in the continuous performance test (CPT). The hypnotic susceptibility of the participants was measured by the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A) and the attentional task was a three minute long auditory version of the CPT. The CPT task was administered four times: before hypnosis (CPT1), after a hypnotic induction (CPT2), after suggestions about speed and accuracy (CPT3), and after the termination of hypnosis (CPT4). The susceptibility of the groups measured by HGSHS:A did not differ. There was a statistically significant decrease in reaction times in both ADHD and control groups between CPT2 and CPT3. The differences between CPT1 and CPT2, even though non-significant, were different in the two groups: in the ADHD group reaction times decreased whereas in the control group they increased. Both groups made very few errors in the short CPT. This study indicates that hypnotic suggestions have an effect on reaction times in the sustained attention task both in adult ADHD patients and control subjects. The theoretical and clinical implications are discussed.

Keywords
Hypnosis, ADHD
National Category
Behavioral Sciences Biology
Identifiers
urn:nbn:se:his:diva-11430 (URN)10.1371/journal.pone.0126497 (DOI)000354542500106 ()25962151 (PubMedID)2-s2.0-84930661222 (Scopus ID)
Available from: 2015-08-26 Created: 2015-08-26 Last updated: 2017-12-04Bibliographically approved
Koivisto, M., Kirjanen, S., Revonsuo, A. & Kallio, S. (2013). A Preconscious Neural Mechanism of Hypnotically Altered Colors: A Double Case Study. PLoS ONE, 8(8), Article ID e70900.
Open this publication in new window or tab >>A Preconscious Neural Mechanism of Hypnotically Altered Colors: A Double Case Study
2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 8, article id e70900Article in journal (Refereed) Published
Abstract [en]

Hypnotic suggestions may change the perceived color of objects. Given that chromatic stimulus information is processed rapidly and automatically by the visual system, how can hypnotic suggestions affect perceived colors in a seemingly immediate fashion? We studied the mechanisms of such color alterations by measuring electroencephalography in two highly suggestible participants as they perceived briefly presented visual shapes under posthypnotic color alternation suggestions such as "all the squares are blue''. One participant consistently reported seeing the suggested colors. Her reports correlated with enhanced evoked upper beta-band activity (22 Hz) 70-120 ms after stimulus in response to the shapes mentioned in the suggestion. This effect was not observed in a control condition where the participants merely tried to simulate the effects of the suggestion on behavior. The second participant neither reported color alterations nor showed the evoked beta activity, although her subjective experience and event-related potentials were changed by the suggestions. The results indicate a preconscious mechanism that first compares early visual input with a memory representation of the suggestion and consequently triggers the color alteration process in response to the objects specified by the suggestion. Conscious color experience is not purely the result of bottom-up processing but it can be modulated, at least in some individuals, by top-down factors such as hypnotic suggestions.

Place, publisher, year, edition, pages
Public Library of Science, 2013
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-8619 (URN)10.1371/journal.pone.0070900 (DOI)000324465000152 ()23940663 (PubMedID)2-s2.0-84881117166 (Scopus ID)
Available from: 2013-11-05 Created: 2013-11-05 Last updated: 2017-12-06Bibliographically approved
Kallio, S. & Koivisto, M. (2013). Posthypnotic Suggestion Alters Conscious Color Perception in an Automatic Manner. International journal of clinical and experimental hypnosis, 61(4), 371-387
Open this publication in new window or tab >>Posthypnotic Suggestion Alters Conscious Color Perception in an Automatic Manner
2013 (English)In: International journal of clinical and experimental hypnosis, ISSN 0020-7144, E-ISSN 1744-5183, Vol. 61, no 4, p. 371-387Article in journal (Refereed) Published
Abstract [en]

The authors studied whether a posthypnotic suggestion to see a brief, masked target as gray can change the color experience of a hypnotic virtuoso. The visibility of the target was manipulated by varying the delay between the target and the mask that followed it. The virtuoso's subjective reports indicated that her conscious color experience was altered already at short delays between the target and the subsequent mask. The virtuoso's objectively measured pattern of responding under posthypnotic suggestion could not be mimicked either by control participants nor the virtuoso herself. Due to posthypnotic amnesia, the virtuoso was unaware of suggestions given during hypnosis. Importantly, the virtuoso could not alter her color perception without a hypnotic suggestion. These results suggest that hypnosis can affect even a highly automatic process such as color perception.

Place, publisher, year, edition, pages
Routledge, 2013
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-8618 (URN)10.1080/00207144.2013.810446 (DOI)000323631600001 ()23957259 (PubMedID)2-s2.0-84883502178 (Scopus ID)
Available from: 2013-11-05 Created: 2013-11-05 Last updated: 2017-12-06Bibliographically approved
Noreika, V., Falter, C. M., Arstila, V., Wearden, J. H. & Kallio, S. (2012). Perception of Short Time Scale Intervals in a Hypnotic Virtuoso. International journal of clinical and experimental hypnosis, 60(3), 318-337
Open this publication in new window or tab >>Perception of Short Time Scale Intervals in a Hypnotic Virtuoso
Show others...
2012 (English)In: International journal of clinical and experimental hypnosis, ISSN 0020-7144, E-ISSN 1744-5183, Vol. 60, no 3, p. 318-337Article in journal (Refereed) Published
Abstract [en]

Previous studies showed that hypnotized individuals underestimate temporal intervals in the range of several seconds to tens of minutes. However, no previous work has investigated whether duration perception is equally disorderly when shorter time intervals are probed. In this study, duration perception of a hypnotic virtuoso was tested using repeated standard temporal generalization and duration estimation tasks. When compared to the baseline state, hypnosis affected perception of intervals spread around 600 ms in the temporal generalization task but did not alter perception of slightly longer intervals spread around 1000 ms. Furthermore, generalization of temporal intervals was more orderly under hypnosis than in the baseline state. In contrast, the hypnotic virtuoso showed a typical time underestimation effect when perception of longer supra-second intervals was tested in the duration estimation task, replicating results of the previous hypnosis studies.

Place, publisher, year, edition, pages
Routledge, 2012
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-6218 (URN)10.1080/00207144.2012.675296 (DOI)000305025700005 ()22681328 (PubMedID)2-s2.0-84862330156 (Scopus ID)
Available from: 2012-08-08 Created: 2012-08-08 Last updated: 2017-12-07Bibliographically approved
Kirsch, I., Cardena, E., Derbyshire, S., Dienes, Z., Heap, M., Kallio, S., . . . Whalley, M. (2011). Definitions of Hypnosis and Hypnotizability and their Relation to Suggestion and Suggestibility: A Consensus Statement. Contemporary Hypnosis, 28(2), 107-115
Open this publication in new window or tab >>Definitions of Hypnosis and Hypnotizability and their Relation to Suggestion and Suggestibility: A Consensus Statement
Show others...
2011 (English)In: Contemporary Hypnosis, ISSN 0960-5290, E-ISSN 1557-0711, Vol. 28, no 2, p. 107-115Article in journal (Refereed) Published
Abstract [en]

This article reports a consensus that was reached at an Advanced Workshop in Experimental Hypnosis held as part of the joint annual conference of the British Society of Medical and Dental Hypnosis (BSMDH) and the British Society of Experimental and Clinical Hypnosis (BSECH). The unanimous consensus was that conventional definitions of hypnosis and hypnotizability are logically inconsistent and that at least one of them needed to be changed. Participants were divided between the alternatives of (1) broadening the operational definition of hypnosis so as to include responding to so-called waking suggestion and (2) limiting the term 'hypnotizability' to the effects of administering a hypnotic induction.

Place, publisher, year, edition, pages
Crown House Publishing, 2011
Keywords
suggestion, suggestibility, hypnosis, hypnotizablity
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-5671 (URN)
Available from: 2012-04-02 Created: 2012-04-02 Last updated: 2017-11-27Bibliographically approved
Kallio, S., Hyönä, J., Revonsuo, A., Sikka, P. & Nummenmaa, L. (2011). The Existence of a Hypnotic State Revealed by Eye Movements. PLoS ONE, 6(10), Article ID e26374.
Open this publication in new window or tab >>The Existence of a Hypnotic State Revealed by Eye Movements
Show others...
2011 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 10, article id e26374Article in journal (Refereed) Published
Place, publisher, year, edition, pages
PLoS ONE, 2011
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-5601 (URN)10.1371/journal.pone.0026374 (DOI)000296515200016 ()22039474 (PubMedID)2-s2.0-80055034195 (Scopus ID)
Available from: 2012-03-12 Created: 2012-03-12 Last updated: 2017-12-07Bibliographically approved
Revonsuo, A., Kallio, S. & Sikka, P. (2009). What is an altered state of consciousness?. Philosophical Psychology, 22(2), 187-204
Open this publication in new window or tab >>What is an altered state of consciousness?
2009 (English)In: Philosophical Psychology, ISSN 0951-5089, E-ISSN 1465-394X, Vol. 22, no 2, p. 187-204Article in journal (Refereed) Published
Abstract [en]

‘‘Altered State of Consciousness’’ (ASC) has been defined as a changed overall pattern of conscious experience, or as the subjective feeling and explicit recognition that one’s own subjective experience has changed. We argue that these traditional definitions fail to draw a clear line between altered and normal states of consciousness (NSC). We outline a new definition of ASC and argue that the proper way to understand the concept of ASC is to regard it as a representational notion: the alteration that has happened is not an alteration of consciousness (or subjective experience) per se, but an alteration in the informational or representational relationships between consciousness and the world. An altered state of consciousness is defined as a state in which the neurocognitive background mechanisms of consciousness have an increased tendency to produce misrepresentations such as hallucinations, delusions, and memory distortions. Paradigm examples of such generally misrepresentational, temporary, and reversible states are dreaming, psychotic episodes, psychedelic drug experiences, some epileptic seizures, and hypnosis in highly hypnotizable subjects. The representational definition of ASC should be applied in the theoretical and empirical studies of ASCs to unify and clarify the conceptual basis of ASC research.

Place, publisher, year, edition, pages
Routledge, 2009
Keywords
ASC, Dreaming, Drug Induced States, Hypnosis, Meditation, Psychosis, State of consciousness
National Category
Natural Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-3009 (URN)10.1080/09515080902802850 (DOI)000264826600004 ()2-s2.0-69249214200 (Scopus ID)
Available from: 2009-05-07 Created: 2009-05-07 Last updated: 2017-12-28Bibliographically approved
Organisations

Search in DiVA

Show all publications