diff --git a/samplebrain/interface/samplebrain.ui b/samplebrain/interface/samplebrain.ui
index 23734f0..6177bbb 100644
--- a/samplebrain/interface/samplebrain.ui
+++ b/samplebrain/interface/samplebrain.ui
@@ -214,6 +214,25 @@
             </item>
            </layout>
           </item>
+          <item>
+           <widget class="QCheckBox" name="checkBoxInvert">
+            <property name="sizeIncrement">
+             <size>
+              <width>0</width>
+              <height>0</height>
+             </size>
+            </property>
+            <property name="text">
+             <string>invert</string>
+            </property>
+            <property name="iconSize">
+             <size>
+              <width>16</width>
+              <height>16</height>
+             </size>
+            </property>
+           </widget>
+          </item>
           <item>
            <spacer name="verticalSpacer_3">
             <property name="orientation">
@@ -1441,6 +1460,22 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>checkBoxInvert</sender>
+   <signal>toggled(bool)</signal>
+   <receiver>MainWindow</receiver>
+   <slot>invert_slot(bool)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>189</x>
+     <y>313</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>361</x>
+     <y>306</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
  <slots>
   <slot>play_slot()</slot>
@@ -1486,5 +1521,6 @@
   <slot>stop_record()</slot>
   <slot>n_ratio_slot(int)</slot>
   <slot>n_ratio_slot(double)</slot>
+  <slot>invert_slot(bool)</slot>
  </slots>
 </ui>
diff --git a/samplebrain/qt/MainWindow.h b/samplebrain/qt/MainWindow.h
index a5c48d3..80a9279 100644
--- a/samplebrain/qt/MainWindow.h
+++ b/samplebrain/qt/MainWindow.h
@@ -49,6 +49,11 @@ private slots:
     void fft2_start_slot(int s){} // { m_renderer->get_params()->m_fft2_start=s; }
     void fft2_end_slot(int s){} // { m_renderer->get_params()->m_fft2_end=s; }
     void volume_slot(int s) { lo_send(m_audio_address,"/volume","f",s/100.0f); }
+    void invert_slot(bool s) { if (s) {
+            lo_send(m_audio_address,"/invert","i",1);
+        } else {
+            lo_send(m_audio_address,"/invert","i",0);
+        }}
     void run_slot() {}
     void load_target() {
         m_last_file=QFileDialog::getOpenFileName(
diff --git a/samplebrain/qt/audio_thread.cpp b/samplebrain/qt/audio_thread.cpp
index b3ade9e..6bfdc06 100644
--- a/samplebrain/qt/audio_thread.cpp
+++ b/samplebrain/qt/audio_thread.cpp
@@ -88,6 +88,9 @@ void audio_thread::process(sample &s, sample &s2) {
         if (name=="/volume") {
             m_renderer->set_volume(cmd.get_float(0)*10);
         }
+        if (name=="/invert") {
+            m_renderer->set_invert(cmd.get_int(0));
+        }
         if (name=="/record") {
             m_renderer->set_playing(true);
             m_audio_device->start_recording(cmd.get_string(0));
diff --git a/samplebrain/qt/generated/ui_samplebrain.h b/samplebrain/qt/generated/ui_samplebrain.h
index a31be08..97480fb 100644
--- a/samplebrain/qt/generated/ui_samplebrain.h
+++ b/samplebrain/qt/generated/ui_samplebrain.h
@@ -1,19 +1,20 @@
 /********************************************************************************
-** Form generated from reading UI file 'samplebrainB32443.ui'
+** Form generated from reading UI file 'samplebrainm32443.ui'
 **
-** Created: Tue Jul 21 15:50:16 2015
+** Created: Tue Jul 21 22:01:28 2015
 **      by: Qt User Interface Compiler version 4.8.1
 **
 ** WARNING! All changes made in this file will be lost when recompiling UI file!
 ********************************************************************************/
 
-#ifndef SAMPLEBRAINB32443_H
-#define SAMPLEBRAINB32443_H
+#ifndef SAMPLEBRAINM32443_H
+#define SAMPLEBRAINM32443_H
 
 #include <QtCore/QVariant>
 #include <QtGui/QAction>
 #include <QtGui/QApplication>
 #include <QtGui/QButtonGroup>
+#include <QtGui/QCheckBox>
 #include <QtGui/QDial>
 #include <QtGui/QDoubleSpinBox>
 #include <QtGui/QGridLayout>
@@ -59,6 +60,7 @@ public:
     QSpinBox *spinBoxFFT1Start;
     QLabel *label_10;
     QSpinBox *spinBoxFFT1End;
+    QCheckBox *checkBoxInvert;
     QSpacerItem *verticalSpacer_3;
     QVBoxLayout *verticalLayout_6;
     QLabel *label_16;
@@ -264,6 +266,13 @@ public:
 
         verticalLayout_3->addLayout(horizontalLayout_3);
 
+        checkBoxInvert = new QCheckBox(controlTab);
+        checkBoxInvert->setObjectName(QString::fromUtf8("checkBoxInvert"));
+        checkBoxInvert->setSizeIncrement(QSize(0, 0));
+        checkBoxInvert->setIconSize(QSize(16, 16));
+
+        verticalLayout_3->addWidget(checkBoxInvert);
+
         verticalSpacer_3 = new QSpacerItem(20, 40, QSizePolicy::Minimum, QSizePolicy::Expanding);
 
         verticalLayout_3->addItem(verticalSpacer_3);
@@ -676,6 +685,7 @@ public:
         QObject::connect(sliderRatio, SIGNAL(valueChanged(int)), MainWindow, SLOT(ratio_slot(int)));
         QObject::connect(sliderNRatio, SIGNAL(valueChanged(int)), MainWindow, SLOT(n_ratio_slot(int)));
         QObject::connect(doubleSpinBoxNRatio, SIGNAL(valueChanged(double)), MainWindow, SLOT(n_ratio_slot(double)));
+        QObject::connect(checkBoxInvert, SIGNAL(toggled(bool)), MainWindow, SLOT(invert_slot(bool)));
 
         tabWidget->setCurrentIndex(0);
 
@@ -692,6 +702,7 @@ public:
         label_7->setText(QApplication::translate("MainWindow", "fft subsection", 0, QApplication::UnicodeUTF8));
         label_9->setText(QApplication::translate("MainWindow", "Start", 0, QApplication::UnicodeUTF8));
         label_10->setText(QApplication::translate("MainWindow", "End", 0, QApplication::UnicodeUTF8));
+        checkBoxInvert->setText(QApplication::translate("MainWindow", "invert", 0, QApplication::UnicodeUTF8));
         label_16->setText(QApplication::translate("MainWindow", "target sound", 0, QApplication::UnicodeUTF8));
         pushButtonLoadTarget->setText(QApplication::translate("MainWindow", "load target", 0, QApplication::UnicodeUTF8));
         label_17->setText(QApplication::translate("MainWindow", "block size", 0, QApplication::UnicodeUTF8));
@@ -743,4 +754,4 @@ namespace Ui {
 
 QT_END_NAMESPACE
 
-#endif // SAMPLEBRAINB32443_H
+#endif // SAMPLEBRAINM32443_H
diff --git a/samplebrain/src/brain.cpp b/samplebrain/src/brain.cpp
index f667f1b..0decb19 100644
--- a/samplebrain/src/brain.cpp
+++ b/samplebrain/src/brain.cpp
@@ -16,6 +16,7 @@
 
 #include <iostream>
 #include <sndfile.h>
+#include <float.h>
 #include <jellyfish/audio.h>
 #include "brain.h"
 
@@ -83,7 +84,7 @@ const block &brain::get_block(u32 index) const {
 
 // returns index to block
 u32 brain::search(const block &target, const search_params &params) const {
-    double closest = 999999999;
+    double closest = FLT_MAX;
     u32 closest_index = 0;
     u32 index = 0;
     for (vector<block>::const_iterator i=m_blocks.begin(); i!=m_blocks.end(); ++i) {
@@ -97,6 +98,22 @@ u32 brain::search(const block &target, const search_params &params) const {
     return closest_index;
 }
 
+// returns index to block
+u32 brain::rev_search(const block &target, const search_params &params) const {
+    double furthest = 0;
+    u32 furthest_index = 0;
+    u32 index = 0;
+    for (vector<block>::const_iterator i=m_blocks.begin(); i!=m_blocks.end(); ++i) {
+        double diff = target.compare(*i,params);
+        if (diff>furthest) {
+            furthest=diff;
+            furthest_index = index;
+        }
+        ++index;
+    }
+    return furthest_index;
+}
+
 // take another brain and rebuild this brain from bits of that one
 // (presumably this one is made from a single sample)
 void brain::resynth(const string &filename, const brain &other, const search_params &params){
diff --git a/samplebrain/src/brain.h b/samplebrain/src/brain.h
index c183f12..9933eb7 100644
--- a/samplebrain/src/brain.h
+++ b/samplebrain/src/brain.h
@@ -60,6 +60,7 @@ public:
     u32 get_overlap() const { return m_overlap; }
 
     u32 search(const block &target, const search_params &params) const;
+    u32 rev_search(const block &target, const search_params &params) const;
 
     static bool unit_test();
 
diff --git a/samplebrain/src/renderer.cpp b/samplebrain/src/renderer.cpp
index 2ee5e10..8d5d8e1 100644
--- a/samplebrain/src/renderer.cpp
+++ b/samplebrain/src/renderer.cpp
@@ -54,7 +54,12 @@ void renderer::process(u32 nframes, float *buf) {
     // get indices for current buffer
     for (u32 tgt_index = tgt_start; tgt_index<=tgt_end; tgt_index++) {
         u32 time=tgt_index*tgt_shift;
-        u32 src_index = m_source.search(m_target.get_block(tgt_index), m_search_params);
+        u32 src_index;
+        if (!m_invert) {
+            src_index = m_source.search(m_target.get_block(tgt_index), m_search_params);
+        } else {
+            src_index = m_source.rev_search(m_target.get_block(tgt_index), m_search_params);
+        }
         // put them in the index list
         m_render_blocks.push_back(render_block(src_index,time));
     }
diff --git a/samplebrain/src/renderer.h b/samplebrain/src/renderer.h
index d340969..b28295c 100644
--- a/samplebrain/src/renderer.h
+++ b/samplebrain/src/renderer.h
@@ -36,6 +36,7 @@ renderer(brain &source, brain &target) :
 
     void set_playing(bool s) { m_playing=s; }
     void set_volume(float s) { m_volume=s; }
+    void set_invert(bool s) { m_invert=s; }
     search_params *get_params() { return &m_search_params; }
 
     static bool unit_test();
@@ -58,7 +59,7 @@ private:
     search_params m_search_params;
     float m_volume;
     bool m_playing;
-
+    bool m_invert;
     std::list<render_block> m_render_blocks;
     u32 m_render_time;
 };