Forensic Applications of Recording the Neurocognitive Processes of Remembrance

Knowing and remembering have been considered two different neurocognitive processes (Mandler 1980), as knowing is essentially a process of recognition where the external model is identified as a known internal model [1]. Remembrance take place when sensorymotor imageries reactivated along with the earlier emotional effects in the individual. It was later supported in several brain imaging studies [2-10]. Registration of signals at the subcortical brain stem areas evokes Brainstem Evoked Potentials, followed by the middle latency evoked potentials arising when the sensory signals arrive in the cortical area, for primary recognition. When the sensory signals reach the middle cortical layer, beyond the brain stem areas, cortical sensory registration of the signals take place, which also leads to attentional arousal, and these processes repeatedly occurring produce a positivity representing continuous sensory (visual) registration (P100/P80) followed by a negativity (N100/N140) representing attentional arousal towards the auditory or visual signals, and another positivity (P200). The time taken for auditory stimuli, these potentials occur faster at 70ms (P70), 100ms (N100) and 160ms (P160) [11]. Recognition of the incoming signals is the next processing stage, when a P300 is generated. What may be recognized could be mere change in the signal characteristics, which may serve a novelty effect or mere detection of the difference. The latter is seen when one must make a response to any change in the input signal. Such need state facilitates detection of even a minor change in the input characteristics, whereas detection of such changes may not occur, if the subject does not need to attend to such minor changes. Recognition of input signals is therefore the most important component of getting to know the changes, wherever such input signals could come from. However, the typical P1-N1-P2and P3, are brief cerebral potentials associated with specific functional roles initiated in the cortex, and these potentials manifest transiently or form only when the signal inputs and their processing are of short duration.


Introduction
Knowing and remembering have been considered two different neurocognitive processes (Mandler 1980), as knowing is essentially a process of recognition where the external model is identified as a known internal model [1]. Remembrance take place when sensorymotor imageries reactivated along with the earlier emotional effects in the individual. It was later supported in several brain imaging studies [2][3][4][5][6][7][8][9][10]. Registration of signals at the subcortical -brain stem areas evokes Brainstem Evoked Potentials, followed by the middle latency evoked potentials arising when the sensory signals arrive in the cortical area, for primary recognition. When the sensory signals reach the middle cortical layer, beyond the brain stem areas, cortical sensory registration of the signals take place, which also leads to attentional arousal, and these processes repeatedly occurring produce a positivity representing continuous sensory (visual) registration (P100/P80) followed by a negativity (N100/N140) representing attentional arousal towards the auditory or visual signals, and another positivity (P200). The time taken for auditory stimuli, these potentials occur faster at 70ms (P70), 100ms (N100) and 160ms (P160) [11]. Recognition of the incoming signals is the next processing stage, when a P300 is generated. What may be recognized could be mere change in the signal characteristics, which may serve a novelty effect or mere detection of the difference.
The latter is seen when one must make a response to any change in the input signal. Such need state facilitates detection of even a minor change in the input characteristics, whereas detection of such changes may not occur, if the subject does not need to attend to such minor changes. Recognition of input signals is therefore the most important component of getting to know the changes, facilitating or negatively debilitating to the self and others, and mold own drive in positive or negative manner, when we call them positive or negative emotional arousal. The sensory-motor contacts and own emotional arousal are experienced as positive or negative and one's emotional expressions through sensory-motor contacts are affected in the same manner. Recognition could be a simple to complex neurocognitive process. Recognition may start essentially as a modality specific simple to complex characteristic. However, if one may assign special meaning to specific characteristics, as in alphabets, numbers, and symbols, when one retrieve/convert what has been received as sensory change into a specific meaning, one has assigned or learned to the sensory inputs. What one retrieves from a knowledge bank using sets of recognized information is essentially knowledge, which remains as bank of mere knowledge. Knowing is essentially possessing information formed from the signals received through real sensory-motor contacts or virtual contacts, which may one attempts and assembles real and equivalent physical contacts and learn to experientially verify them. One learns to assemble the such value-based relationships at conceptual levels, and one learns to experientially validate the outcome effects. Sensory-motor contacts are made in virtual formats with the same relationships so that the outcome forms in predefined and predicted manner.
Individuals store in memory huge knowledge bank and skills and retrieve relevant information and skills from the knowledge bank and skill-store for external expressions and creative works. What may be externally stored are often not mere basic information alone for facilitating knowledge, but huge capabilities for learning, managing, and creating new relationships with their positive and negative outcomes. Dealing with virtual realities, allow one to experiment as well as create new relationships.

Experiencing Sensory-Motor Contacts
Experiencing sensory-motor contacts with reality and the cognitive interpretations and judgments of associated emotional arousal constitute experience of an individual. An experience has therefore molded emotional effects and interpreted sensorymotor contacts. Retrieval of an experience is remembrance of the interpreted sensory-motor contacts, and molded emotional effects, all of which are personally constituted. The brain activation in remembrance is almost recreation of the experiential effects in the individual, unlike mere retrieval of knowledge. Mander in the early years (1980) itself differentiated knowing from remembrance, which was later supported by several authors in their studies [2][3][4][5][6][7][8][9][10][12][13][14][15][16][17][18][19][20][21][22][23] [17] found that autobiographical recall produced greater activation of medial prefrontal cortex, visual and para hippocampal region and hippocampus, representing self-referential processing effect, visual and spatial memory effect, and recall effect respectively. These studies showed that activation during remembrance generally extended across the anterior and posterior parts of the middle temporal gyrus spreading into superior temporal sulcus, tempero-parietal junction, middle and superior frontal gyri, anterior paracingulate and cingulate gyri and left inferior orbital frontal gyrus pars orbitalis. On the other hand, pure semantic retrieval always produced activation of bilateral supramarginal and inferior frontal cortices, left insular cortex, and inferior temporal gyrus.  speech may activate various subcortical and cortical areas directly related to emotional arousal [42][43][44]. This has been also reported in multiple lesion studies [42][43][44][45]. Presence of the same emotional arousal in normal brain would then reactivate the same areas of the brain during their remembrance.

Recreation of Sensory-Motor Activations in the Brain
Another important component of remembrance is the recreation of the various sensory-motor imageries that one recognized during an experience. The recreation of the sensory-motor imageries constitutes reexperience of the earlier experience, when and with the same emotional effects. There have been several studies which have shown such sensory-motor reactivation during remembrance based on the primary activation experienced [46][47][48][49][50][51][52]. Similar effects have been seen with regard to reactivation of motor imageries [53][54][55][56][57][58][59]. Sensory-motor reactivation of an original experience is a virtual reexperience of the original behavioral and perceptual activation, which the individual could semantically express again and become verbally aware of the entire experience, its genesis, direction, intensity, and outcome effects. Ganis et al. [47] in their neuroimaging study found that frontal and parietal areas have more specific roles in recreating visuospatial imageries and their integration. Remembrance of a past activity therefore, facilitates recreation of a virtual world based on the original experiences, and one could go through the reexperience of the virtual world recreated in the brain. However, such reexperience is possible only if one has had a real experience earlier. A semantic recreation of an experience may not succeed even in the recreation of a virtual world which may resemble the real original experience. One may partly succeed in the recreation of a virtual experience, even though the components may not be drawn from a real experience. This is indeed the reflection of the dramatic capability of an individual. One may be able to pretend that one is reexperiencing sensorymotor imageries, without having the recreation of the imageries in the brain. One the other hand, one may be able to recreate the brain imageries based on another similar experience, and pretend that one is remembering an original experience, which one has not had. However, one may need lot of practice and capability to recreate brain stimulation resembling such virtual experiences and emotionally react to them. Virtual recreation of sensorymotor imageries in the brain is indeed very different from the self-recreation of an earlier real imagery and its experience, which may take place automatically, while making online sensory-motor contacts.

Recording Remembrance of Experience
An important forensic task has always been to elicit the truth from individuals, who may be taken in as suspects with some specific involvement in a crime already committed. It is a general phenomenon that the person who has really committed a criminal act may want to hide his or her involvement in the criminal activity and pretend to be innocent. Detection of the crime and eliciting the truth and involvement in a criminal act has always been a most difficult investigative task, as individuals invariably hide the truth and try to implicate others as responsible for the criminal activity.
Detection of significant physiological responsible generally present when a person makes an untrue revelation has been the commonly used Polytrophic method of lie detection. However, knowing that one may be telling a lie, may only party help in the process of crime investigation. Another method that was tried out was related to recognition of crime related objects and information, when a person may produce significant increase in the P300 event related potential while recognizing such objects or information which one might have made use of. Another related method was to search for a memory recall while recognizing such objects or information.
However, it was again based on an event related potential generally recoded in s single channel EEG system. Yet another method that came to be successfully used was related to recording several neural changes during remembrance of crime related events, which automatically takes place, even if the subject does not have to give any response at all. Cueing of remembrance takes place using short sentences referring to various stages of actions and responses that could have taken place. Remembrance automatically takes place while listening to short sentences (probes) which refer to the multiple actions and responses that could have taken place.
Significant remembrance profile occurs only in those who were present in the crime scenario, including those who could have been directly involved in committing the crime. The remembrance responses are captured in multichannel EEG, which could reflect the neural changes from a total top of the brain giving a vast topographical representation of changes.

Cueing Remembrance
Cued remembrance has been used as basic process for detecting presence of neural processes in the brain, which could be present only if one could remember or recreate the experience of a past response or action, which may also recreate an earlier emotional experience in a person. The presence of multiple neural processes associated with remembrance is taken to indicate the presence of related experiences in a person, which he or she could have acquired only if her participated in the related activity. Cueing is a process of prompting or triggering one to remember a specific act or event, when all the related neural processes will automatically be recreated in the brain. One may be cued by several short sentences, so that one is prompted to remember sequence of experiences related to events or actions. One is not expected to respond to the

EEG Correlates of Neurocognitive Processing
Electrophysiological studies with surface electrodes have been Desynchronization of alpha is always accompanied by increased beta activity and hence increase in beta activity has been considered associated with the presence of cognitive processing, when greater neural resources are utilized in the brain. Changes in the power of delta, theta, high alpha and gamma oscillations were considered to be of cognitive significance [63][64][65][66][67][68][69] found that delta band frequencies have such specific association with awareness of internal processing. Robinson [70] reported that 4Hz activity is related to behavioural arousal and it is negatively related to 10 Hz activity. The cognitive roles of theta and alpha frequencies ranges have been demonstrated in several studies [71][72][73][74]. Rohm et al [75] found that visually presented sentence processing caused greater theta activity whereas upper alpha increased only when there was semantic demand during the processing. On the other hand, beta activity is induced in all conditions when there is cognitive demand, and the activity subsides when the demand is completed. It was found that beta activity has been associated with mental motor imageries, which has been repeatedly seen in BEOS tests. Increase in beta activity was seen over the primary motor cortex even during action observation [76] indicating the possibility of presence of motor imagery produced by mirror neurons. In a comparative study of Pet and EEG Nakamura et al. [43] found that beta power was positively correlated with rCBF in the prefrontal cortices including the anterior cingulate, while participants listened to music. Olufsen et al. [77] found that gamma (30-80Hz) and beta (12- [78][79][80][81][82][83]. Increase in the coherence of gamma activity across left frontoparietal areas is an indication of the frontal lobes recruiting neural structures from the parietal areas for common functional involvement, during remembrance of visual mental imageries (Mukundan 2005). The frontal participation is associated with the use and recall of the verbally transcoded information from which the visual mental imagery can be reconstituted, which is accomplished in the posterior brain areas.
Desynchronization of alpha rhythms is always noticed, while listening to auditory probes. This is considered to indicate the registration of the probe in the brain, which is always seen in the very early stage of probe presentation in all channels. While listening to probes, this is always followed by significant increase in the high alpha and beta rhythms, indicating presence of encoding process, needed for interpretation of the meaning of the inputs.
These changes may be followed by occurrence of remembrance of a past experiential episode, if at all one has had such experience, which may also be accompanied by significant increase in gamma activity as one would need to produce sensory-motor imageries The non-invasive procedure used in regular EEG procedure without having to give any response to the statements one is expected to listen to, allows a subject to take part in the study for long duration, as well as carry out repetition of the procedure. A suspect would sit and listen to the probes silently without any apparent anxiety or objection as he is not expected to give any response. Further several of the probes refer to actions really carried out by a person, which the subject would fully agree with. Forensic investigation in which the suspect only needs verbal statements without having to give nay response is during forensic investigative procedures. That the BEOS is a procedure, in which the subject has to only hear the auditory probes, whether one may agree with it or not, do not cause discomfort as one could listen to the probes without giving any oral or behavioural response, which gives immense self-confidence to a person to submit oneself to the test procedure. The BEOS test could be repeated on a person using the same probes and could obtain the same results. That a person may be subjected to listen to the probes constituting different formulations of actions further strengthens his or her willingness for the test. A subject may try to think of other events or carry out other mental processing such as preying etc. However, the system continuously measures and online analyses the EEG, and any indication of a person carrying out an alternate cognitive process, blocks the automatic presentation of the probes. Each suspect is given a task that he or she must listen to the probes and try to remember the probes after completion of the test, by writing them down from memory. BEOS findings are currently recommended not to accept as direct evidence in a court of law, as we are making an interpretation based on the presence of neural changes of remembrance that the person has carried out a specific task. The test findings are used for further interrogations and investigations leading to confessions as well as other evidence, acceptable in the courts of law. This has been a highly successful task as several hundreds of cases could be solved by conducting